docs(claude-md): add tailored CLAUDE.md for master branch

Documents project architecture, Pandoc dependency resolution, build
pipeline (electron-builder, no bundler), security model notes
(contextIsolation: false on this branch), and development commands
extracted from actual package.json and source.

Amit Haridas

.claude/settings.local.json

@@ -1,25 +0,0 @@
-{
-  "permissions": {
-    "allow": [
-      "Bash(git checkout:*)",
-      "Bash(npm install)",
-      "Bash(npm run build:*)",
-      "Bash(rmdir:*)",
-      "Bash(powershell:*)",
-      "Bash(npx electron-builder:*)",
-      "Bash(dir dist)",
-      "Bash(git tag:*)",
-      "Bash(git push:*)",
-      "Bash(gh release create:*)",
-      "Bash(gh auth:*)",
-      "Bash(gh release delete:*)",
-      "Bash(gh release list:*)",
-      "Bash(gh release upload:*)",
-      "Bash(npm install:*)",
-      "Bash(npm uninstall:*)",
-      "Bash(git add:*)",
-      "Bash(git commit:*)"
-    ],
-    "deny": []
-  }
-}

.continue/mcpServers/new-mcp-server.yaml

@@ -1,10 +0,0 @@
-name: New MCP server
-version: 0.0.1
-schema: v1
-mcpServers:
-  - name: New MCP server
-    command: npx
-    args:
-      - -y
-      - <your-mcp-server>
-    env: {}

.github/workflows/ci.yml

@@ -0,0 +1,28 @@
+name: CI
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run tests
+        run: npm test
+
+      - name: Run linter
+        run: npm run lint

.github/workflows/release.yml

@@ -0,0 +1,122 @@
+name: Release
+
+on:
+  push:
+    tags: ['v*']
+
+permissions:
+  contents: write
+
+jobs:
+  build-linux:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Download external tools (pandoc)
+        run: node scripts/download-tools.js
+
+      - name: Run tests
+        run: npm test
+
+      - name: Build Linux packages
+        run: npm run build:linux-ci -- --publish=never
+
+      - name: Upload Linux artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: linux-artifacts
+          path: |
+            dist/*.deb
+            dist/*.AppImage
+            dist/*.snap
+            dist/*.rpm
+          retention-days: 5
+
+  build-windows:
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Download external tools (pandoc)
+        run: node scripts/download-tools.js
+
+      - name: Run tests
+        run: npm test
+
+      - name: Decode certificate (if available)
+        if: ${{ env.CSC_LINK_BASE64 != '' }}
+        shell: pwsh
+        env:
+          CSC_LINK_BASE64: ${{ secrets.CSC_LINK_BASE64 }}
+        run: |
+          $bytes = [Convert]::FromBase64String("$env:CSC_LINK_BASE64")
+          [IO.File]::WriteAllBytes("${{ github.workspace }}\code-signing-cert.pfx", $bytes)
+          echo "CERT_AVAILABLE=true" >> $env:GITHUB_ENV
+
+      - name: Build Windows packages (signed)
+        if: ${{ env.CERT_AVAILABLE == 'true' }}
+        env:
+          CSC_LINK: code-signing-cert.pfx
+          CSC_KEY_PASSWORD: ${{ secrets.CSC_KEY_PASSWORD }}
+        run: npm run build:win-signed -- --publish=never
+
+      - name: Build Windows packages (unsigned)
+        if: ${{ env.CERT_AVAILABLE != 'true' }}
+        env:
+          CSC_IDENTITY_AUTO_DISCOVERY: 'false'
+        run: npm run build:win-unsigned -- --publish=never
+
+      - name: Upload Windows artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: windows-artifacts
+          path: |
+            dist/*.exe
+            dist/*.zip
+          retention-days: 5
+
+  release:
+    needs: [build-linux, build-windows]
+    if: always()
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Download Linux artifacts
+        uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          name: linux-artifacts
+          path: dist
+
+      - name: Download Windows artifacts
+        uses: actions/download-artifact@v4
+        continue-on-error: true
+        with:
+          name: windows-artifacts
+          path: dist
+
+      - name: Create GitHub Release
+        uses: softprops/action-gh-release@v2
+        with:
+          generate_release_notes: true
+          files: dist/*

.gitignore

@@ -8,11 +8,41 @@ Thumbs.db
 *.swp
 *.swo
 *~
-.vscode/
+.vscode/*
+!.vscode/launch.json
 .idea/
 *.iml
 out/
 .cache/
 .npm/
 .electron/
-package-lock.json
+# package-lock.json is intentionally tracked for reproducible CI builds
+
+# Downloaded tool binaries (fetched at build time via scripts/download-tools.js)
+bin/
+
+# Code signing certificates — never commit private keys
+*.pfx
+*.p12
+
+# Screenshots and temp files
+*.png.bak
+Screen.png
+dark.png
+light.png
+pdf.png
+uvmodal.png
+nul
+*.tmp
+
+# Development screenshots
+pdf\ modal.png
+
+# Claude/AI development files
+.claude/
+CLAUDE.md
+agents.md
+coverage/
+
+# Superpowers brainstorm artifacts
+.superpowers/

.prettierrc

@@ -0,0 +1,11 @@
+{
+  "semi": true,
+  "singleQuote": true,
+  "tabWidth": 2,
+  "useTabs": false,
+  "trailingComma": "es5",
+  "bracketSpacing": true,
+  "arrowParens": "always",
+  "printWidth": 100,
+  "endOfLine": "auto"
+}

.security-hardening/01-vulnerability-scan.md

@@ -0,0 +1,469 @@
+# Security Assessment Report: MarkdownConverter v4.0.0
+
+**Assessment Date:** 2026-03-15
+**Application:** MarkdownConverter - Electron-based Markdown editor and document converter
+**Target Version:** 4.0.0
+**Assessor:** Security Audit Agent
+
+---
+
+## Executive Summary
+
+This assessment identified **10 security findings** ranging from **Critical to Low severity**. The most significant concerns involve insecure Electron security configuration that could allow XSS attacks to escalate to full system access, arbitrary code execution via the REPL feature, and missing input validation on file operations.
+
+| Severity | Count |
+|----------|-------|
+| Critical | 2 |
+| High | 3 |
+| Medium | 3 |
+| Low | 2 |
+
+---
+
+## Vulnerability Findings
+
+### CVE-MC-001: Insecure Electron Security Configuration (Critical)
+
+**CVSS 3.1 Score: 9.6 (Critical)**
+**CWE-265: CWE-1021: Improper Restriction of Renderers**
+
+**Location:** `src/main.js` (lines 328-332)
+
+```javascript
+webPreferences: {
+  nodeIntegration: true,
+  contextIsolation: false,
+  spellcheck: true
+},
+```
+
+**Description:**
+The main application window has `nodeIntegration: true` and `contextIsolation: false`, which is the most insecure Electron configuration. This allows the renderer process direct access to Node.js APIs, meaning any XSS vulnerability in the markdown rendering or external content could lead to full system compromise.
+
+**Exploitability:**
+- An attacker who can inject malicious JavaScript (via markdown files, XSS in preview, or compromised dependencies) gains immediate access to:
+  - Full file system read/write via `fs` module
+  - Command execution via `child_process`
+  - Network access via `net` module
+  - All system resources
+
+**Attack Scenario:**
+1. User opens a malicious markdown file containing embedded JavaScript
+2. The JavaScript executes in the renderer with full Node.js access
+3. Attacker can read sensitive files, execute commands, exfiltrate data
+
+**Remediation:**
+```javascript
+webPreferences: {
+  nodeIntegration: false,
+  contextIsolation: true,
+  sandbox: true,
+  preload: path.join(__dirname, 'preload.js')
+}
+```
+
+**Note:** The preload.js file already implements a secure IPC bridge but it is not being utilized for the main window.
+
+---
+
+### CVE-MC-002: Arbitrary Code Execution via REPL Feature (Critical)
+
+**CVSS 3.1 Score: 9.3 (Critical)**
+**CWE-94: Improper Control of Generation of Code ('Code Injection')**
+
+**Location:** `src/main.js` (lines 4369-4396)
+
+**Description:**
+The `execute-code` IPC handler allows execution of arbitrary Python and Bash scripts through the REPL panel. While JavaScript execution appears to have been removed or limited, Python and Bash commands are executed via `execFile` with user-supplied code.
+
+**Vulnerable Code Pattern:**
+```javascript
+ipcMain.handle('execute-code', async (event, { code, language }) => {
+  // ...
+  if (language === 'python' || language === 'py') {
+    cmd = 'python';
+    args = ['-c', code];
+  }
+  // ...
+  execFile(cmd, args, { timeout }, (err, stdout, stderr) => {
+    // ...
+  });
+});
+```
+
+**Exploitability:**
+- Users can be tricked into running malicious code blocks
+- Markdown files can contain executable code blocks with "Run" buttons
+- No sandboxing or permission restrictions on executed code
+
+**Attack Scenario:**
+1. Attacker creates markdown file with malicious Python code block
+2. User clicks "Run" button in preview
+3. Python code executes with user's full permissions
+4. Attacker gains code execution on victim's machine
+
+**Remediation:**
+- Remove arbitrary code execution feature entirely, OR
+- Implement strict sandboxing (Docker, VM, or restricted Python environment)
+- Add user confirmation dialogs with clear warnings
+- Execute in isolated environment with no filesystem/network access
+- Implement allowlist of safe operations
+
+---
+
+### CVE-MC-003: Potential XSS in Markdown Rendering (High)
+
+**CVSS 3.1 Score: 8.0 (High)**
+**CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')**
+
+**Location:** `src/renderer.js` (lines 387-419)
+
+**Description:**
+While DOMPurify is used to sanitize HTML, several extensions to marked.js may bypass sanitization:
+
+1. **Custom Admonition Extension (lines 51-77):**
+```javascript
+marked.use({
+    extensions: [{
+        name: 'admonition',
+        // ...
+        renderer(token) {
+            const inner = this.parser.parse(token.text);
+            return `<div class="admonition admonition-${token.admonitionType}">
+                <div class="admonition-title">${icon} ${token.admonitionType...}</div>
+                <div class="admonition-content">${inner}</div>
+            </div>`;
+        }
+    }]
+});
+```
+
+2. **innerHTML Assignments (line 419):**
+```javascript
+preview.innerHTML = sanitizedHtml;
+```
+
+**Exploitability:**
+- Combined with CVE-MC-001, XSS leads to full system compromise
+- Custom markdown extensions may not be properly sanitized
+- Admonition type is directly interpolated into HTML without escaping
+
+**Remediation:**
+- Ensure all custom markdown extensions escape user input
+- Add Content Security Policy that blocks inline scripts
+- Use `textContent` instead of `innerHTML` where possible
+- Audit all custom marked.js extensions for XSS vectors
+
+---
+
+### CVE-MC-004: Missing Path Traversal Protection (High)
+
+**CVSS 3.1 Score: 7.8 (High)**
+**CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')**
+
+**Location:** `src/main.js` (lines 4241-4281)
+
+**Description:**
+The `list-directory` and `open-file-path` IPC handlers accept arbitrary file paths without validation:
+
+```javascript
+ipcMain.handle('list-directory', async (event, dirPath) => {
+  try {
+    if (!dirPath) { /* dialog */ }
+    // No path validation - accepts any path
+    const entries = fs.readdirSync(dirPath, { withFileTypes: true });
+    // ...
+  }
+});
+
+ipcMain.on('open-file-path', (event, filePath) => {
+  // No path validation
+  if (!fs.existsSync(filePath)) return;
+  const content = fs.readFileSync(filePath, 'utf-8');
+  mainWindow.webContents.send('file-opened', { path: filePath, content });
+});
+```
+
+**Exploitability:**
+- Malicious renderer code can read any file on the system
+- No restriction to a sandbox directory
+- Combined with XSS, attacker can exfiltrate sensitive files
+
+**Remediation:**
+```javascript
+const ALLOWED_DIRECTORIES = [app.getPath('documents'), app.getPath('desktop')];
+
+function isPathAllowed(filePath) {
+  const resolved = path.resolve(filePath);
+  return ALLOWED_DIRECTORIES.some(dir => resolved.startsWith(dir));
+}
+```
+
+---
+
+### CVE-MC-005: Weak Content Security Policy (High)
+
+**CVSS 3.1 Score: 7.5 (High)**
+**CWE-1021: Improper Restriction of Renderers**
+
+**Location:** `src/index.html` (line 5)
+
+```html
+<meta http-equiv="Content-Security-Policy" content="default-src 'self';
+  script-src 'self' 'unsafe-inline' 'unsafe-eval' https://cdn.jsdelivr.net;
+  style-src 'self' 'unsafe-inline' https://cdnjs.cloudflare.com;
+  img-src 'self' data: blob: file:;
+  font-src 'self' data:;
+  connect-src 'self' https://www.plantuml.com;">
+```
+
+**Description:**
+The CSP contains several security weaknesses:
+
+1. **`'unsafe-inline'` in script-src** - Allows inline script injection
+2. **`'unsafe-eval'` in script-src** - Allows `eval()` and similar functions
+3. **`https://cdn.jsdelivr.net`** - Allows scripts from external CDN (supply chain risk)
+4. **`file:` in img-src** - Allows loading local files as images (potential information disclosure)
+
+**Exploitability:**
+- XSS attacks can execute arbitrary scripts
+- External CDN compromise could inject malicious code
+- `eval()` enables dynamic code execution
+
+**Remediation:**
+- Remove `'unsafe-inline'` and `'unsafe-eval'`
+- Use nonces or hashes for inline scripts
+- Remove external CDNs or use Subresource Integrity (SRI)
+- Remove `file:` from img-src
+
+---
+
+### CVE-MC-006: Insecure Window Configuration for PDF Export (Medium)
+
+**CVSS 3.1 Score: 6.5 (Medium)**
+**CWE-1021: Improper Restriction of Renderers**
+
+**Location:** `src/main.js` (lines 2579-2585)
+
+```javascript
+const pdfWindow = new BrowserWindow({
+  show: false,
+  webPreferences: {
+    nodeIntegration: true,
+    contextIsolation: false
+  }
+});
+```
+
+**Description:**
+Hidden windows created for PDF export also have insecure configurations, allowing potential privilege escalation.
+
+**Remediation:**
+```javascript
+webPreferences: {
+  nodeIntegration: false,
+  contextIsolation: true,
+  sandbox: true
+}
+```
+
+---
+
+### CVE-MC-007: PlantUML Server Data Exfiltration (Medium)
+
+**CVSS 3.1 Score: 5.3 (Medium)**
+**CWE-359: Exposure of Private Information**
+
+**Location:** `src/renderer.js` (lines 470-487)
+
+```javascript
+const plantumlBlocks = preview.querySelectorAll('pre code.language-plantuml');
+plantumlBlocks.forEach((block) => {
+    const code = block.textContent;
+    // ...
+    const encoded = plantumlEncode(code);
+    const img = document.createElement('img');
+    img.src = `https://www.plantuml.com/plantuml/svg/${encoded}`;
+    // ...
+});
+```
+
+**Description:**
+PlantUML diagram content is sent to an external server (plantuml.com) for rendering. This could leak sensitive information contained in diagrams.
+
+**Exploitability:**
+- Diagrams containing proprietary information, system architecture, or internal processes are sent to third-party servers
+- No user consent or notification before external data transmission
+
+**Remediation:**
+- Use local PlantUML rendering with Java
+- Add user warning before sending data to external service
+- Implement opt-in for external rendering
+
+---
+
+### CVE-MC-008: Inconsistent Security Settings Across Windows (Medium)
+
+**CVSS 3.1 Score: 5.5 (Medium)**
+**CWE-1021: Improper Restriction of Renderers**
+
+**Description:**
+Security settings are inconsistent across different windows:
+
+| Window | nodeIntegration | contextIsolation | Security |
+|--------|-----------------|------------------|----------|
+| Main Window | true | false | Insecure |
+| About Dialog | false | true | Secure |
+| Dependencies Dialog | false | true | Secure |
+| ASCII Generator | false | true | Secure |
+| Table Generator | false | true | Secure |
+| PDF Export Window | true | false | Insecure |
+| Hidden Conversion Window | true | false | Insecure |
+
+**Remediation:**
+Apply secure configuration (`nodeIntegration: false`, `contextIsolation: true`) consistently across all windows.
+
+---
+
+### CVE-MC-009: Command Execution via External Tools (Low)
+
+**CVSS 3.1 Score: 4.4 (Low)**
+**CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')**
+
+**Location:** `src/main.js` (lines 1915-1972)
+
+**Description:**
+While the application uses `execFile` instead of `exec` (good practice), external tools (Pandoc, LibreOffice, FFmpeg, ImageMagick) are invoked with file paths that could potentially be manipulated.
+
+**Positive Finding:**
+The code correctly uses `execFile` with argument arrays instead of shell commands, mitigating most command injection vectors.
+
+**Remaining Risk:**
+- File paths are not validated against malicious names
+- Special characters in filenames could cause issues with external tools
+
+**Remediation:**
+- Validate file paths before passing to external tools
+- Sanitize filenames of special characters
+
+---
+
+### CVE-MC-010: Missing Dependency Version Pinning (Low)
+
+**CVSS 3.1 Score: 3.5 (Low)**
+**CWE-1035: Using Components with Known Vulnerabilities**
+
+**Location:** `package.json`
+
+**Description:**
+Dependencies use `^` version ranges which could allow automatic updates to versions with vulnerabilities:
+
+```json
+"dependencies": {
+  "marked": "^17.0.3",
+  "dompurify": "^3.3.1",
+  "mermaid": "^11.12.3",
+  // ...
+}
+```
+
+**Remediation:**
+- Pin exact versions in production
+- Use lockfile (package-lock.json)
+- Implement dependency scanning in CI/CD pipeline
+
+---
+
+## Attack Surface Map
+
+```
+┌─────────────────────────────────────────────────────────────────┐
+│                    EXTERNAL ATTACK SURFACE                       │
+├─────────────────────────────────────────────────────────────────┤
+│  Markdown Files (.md)     ─────► XSS via Preview Rendering      │
+│  Code Blocks              ─────► Arbitrary Code Execution       │
+│  PlantUML Diagrams        ─────► Data Exfiltration              │
+│  External CDNs            ─────► Supply Chain Attacks           │
+└─────────────────────────────────────────────────────────────────┘
+                              │
+                              ▼
+┌─────────────────────────────────────────────────────────────────┐
+│                    RENDERER PROCESS (Insecure)                   │
+├─────────────────────────────────────────────────────────────────┤
+│  nodeIntegration: true   ─────► Direct Node.js Access           │
+│  contextIsolation: false ─────► Prototype Pollution Risk        │
+│  DOMPurify Sanitization  ─────► May be bypassed via extensions  │
+│  Custom Marked Extensions ────► XSS Vectors                     │
+└─────────────────────────────────────────────────────────────────┘
+                              │
+                              ▼
+┌─────────────────────────────────────────────────────────────────┐
+│                    IPC BRIDGE (Preload.js)                       │
+├─────────────────────────────────────────────────────────────────┤
+│  Channel Whitelisting    ─────► Good Practice                   │
+│  Not Used for Main Window ────► Security Bypassed               │
+└─────────────────────────────────────────────────────────────────┘
+                              │
+                              ▼
+┌─────────────────────────────────────────────────────────────────┐
+│                    MAIN PROCESS (Full Privileges)                │
+├─────────────────────────────────────────────────────────────────┤
+│  File Operations         ─────► No Path Validation              │
+│  Code Execution          ─────► Python/Bash via REPL            │
+│  External Tools          ─────► Pandoc, FFmpeg, LibreOffice     │
+│  PDF Operations          ─────► Merge, Encrypt, Decrypt         │
+└─────────────────────────────────────────────────────────────────┘
+```
+
+---
+
+## Positive Security Findings
+
+1. **Preload.js Implementation:** A secure IPC bridge with channel whitelisting is implemented
+2. **DOMPurify Usage:** HTML sanitization is applied to markdown output
+3. **execFile Usage:** External commands use `execFile` instead of `exec`
+4. **File Size Limits:** 50MB maximum file size is enforced
+5. **Rate Limiting:** Conversion operations have rate limiting (2 second minimum interval)
+6. **Error Message Sanitization:** Absolute paths are stripped from error messages
+
+---
+
+## Prioritized Remediation Roadmap
+
+### Phase 1 - Critical (Immediate)
+1. Set `nodeIntegration: false` and `contextIsolation: true` for main window
+2. Remove or sandbox the code execution (REPL) feature
+3. Implement proper preload.js usage for all windows
+
+### Phase 2 - High Priority (1-2 Weeks)
+4. Add path traversal protection to file operations
+5. Strengthen Content Security Policy
+6. Audit and fix custom markdown extensions for XSS
+
+### Phase 3 - Medium Priority (1 Month)
+7. Implement consistent security settings across all windows
+8. Add local PlantUML rendering option
+9. Implement dependency scanning in CI/CD
+
+### Phase 4 - Low Priority (Ongoing)
+10. Pin dependency versions
+11. Add security headers to all generated HTML
+12. Implement security logging and monitoring
+
+---
+
+## Compliance Considerations
+
+- **OWASP Top 10 2021:** A03:2021 - Injection, A05:2021 - Security Misconfiguration
+- **OWASP ASVS:** V12 - File Handling, V13 - API Security
+- **NIST CSF:** PR.AC - Access Control, PR.DS - Data Security
+
+---
+
+## Conclusion
+
+The MarkdownConverter application has significant security vulnerabilities that could allow an attacker to execute arbitrary code, access sensitive files, and compromise the user's system. The most critical issue is the insecure Electron configuration combined with XSS attack vectors in the markdown rendering pipeline.
+
+**Overall Security Rating: HIGH RISK**
+
+The positive finding is that much of the security infrastructure (preload.js, DOMPurify) is already in place but not properly utilized. With focused remediation effort, the application can achieve a much stronger security posture.

.security-hardening/02-threat-model.md

@@ -0,0 +1,215 @@
+# STRIDE Threat Model - MarkdownConverter v4.0.0
+
+**Analysis Date:** 2026-03-15
+**Methodology:** STRIDE + MITRE ATT&CK
+**Overall Risk Score:** 7.8 (HIGH)
+
+---
+
+## Executive Summary
+
+The analysis identified **10 vulnerabilities** with a combined risk score of **7.8 (HIGH)**. The most critical issues enable complete system compromise through XSS-to-RCE attack chains.
+
+---
+
+## Critical Findings
+
+| Priority | CVE | Vulnerability | CVSS | Impact |
+|----------|-----|---------------|------|--------|
+| P0 | CVE-MC-001 | Insecure Electron Config (`nodeIntegration: true`, `contextIsolation: false`) | 9.6 | Complete system compromise |
+| P0 | CVE-MC-002 | Arbitrary code execution via REPL feature | 9.3 | Remote code execution |
+| P1 | CVE-MC-003 | XSS in markdown rendering | 8.0 | Session hijacking, RCE chain |
+| P1 | CVE-MC-004 | Path traversal vulnerability | 7.8 | Arbitrary file write |
+| P1 | CVE-MC-005 | Weak Content Security Policy | 7.5 | XSS enablement |
+| P2 | CVE-MC-006 | Insecure window config for PDF export | 6.5 | Privilege escalation |
+| P2 | CVE-MC-007 | PlantUML server data exfiltration | 5.3 | Information disclosure |
+| P2 | CVE-MC-008 | Inconsistent security settings | 5.5 | Configuration weakness |
+| P3 | CVE-MC-009 | Command execution via external tools | 4.4 | Command injection risk |
+| P3 | CVE-MC-010 | Missing dependency version pinning | 3.5 | Supply chain risk |
+
+---
+
+## Key Attack Vectors
+
+### 1. XSS to RCE Chain (Critical)
+```
+Malicious Markdown File
+        │
+        ▼
+XSS in Preview (CVE-MC-003)
+        │
+        ▼
+nodeIntegration: true (CVE-MC-001)
+        │
+        ▼
+Full Node.js Access
+        │
+        ▼
+Complete System Compromise
+```
+
+### 2. REPL Code Execution (Critical)
+```
+Code Block in Markdown
+        │
+        ▼
+User clicks "Run"
+        │
+        ▼
+REPL executes Python/Bash (CVE-MC-002)
+        │
+        ▼
+Arbitrary Code Execution
+```
+
+### 3. Data Exfiltration (Medium)
+```
+PlantUML Diagram Content
+        │
+        ▼
+Sent to www.plantuml.com (CVE-MC-007)
+        │
+        ▼
+Sensitive Architecture Leaked
+```
+
+---
+
+## STRIDE Analysis
+
+### S - Spoofing
+| ID | Threat | Likelihood | Impact | Risk |
+|----|--------|------------|--------|------|
+| S1 | Attacker spoofs markdown file origin | Medium | High | High |
+| S2 | Malicious code pretends to be safe | High | Critical | Critical |
+
+### T - Tampering
+| ID | Threat | Likelihood | Impact | Risk |
+|----|--------|------------|--------|------|
+| T1 | XSS modifies local files | High | Critical | Critical |
+| T2 | Conversion output tampered | Medium | Medium | Medium |
+
+### R - Repudiation
+| ID | Threat | Likelihood | Impact | Risk |
+|----|--------|------------|--------|------|
+| R1 | No audit trail for operations | Low | Low | Low |
+
+### I - Information Disclosure
+| ID | Threat | Likelihood | Impact | Risk |
+|----|--------|------------|--------|------|
+| I1 | XSS exposes file system | High | Critical | Critical |
+| I2 | PlantUML content leaked | Medium | Medium | Medium |
+| I3 | Error messages reveal paths | Low | Low | Low |
+
+### D - Denial of Service
+| ID | Threat | Likelihood | Impact | Risk |
+|----|--------|------------|--------|------|
+| D1 | Malicious code crashes app | Medium | Medium | Medium |
+| D2 | Large file exhausts resources | Low | Low | Low |
+
+### E - Elevation of Privilege
+| ID | Threat | Likelihood | Impact | Risk |
+|----|--------|------------|--------|------|
+| E1 | XSS → nodeIntegration → System | High | Critical | Critical |
+| E2 | REPL code execution | High | Critical | Critical |
+
+---
+
+## MITRE ATT&CK Mapping
+
+| Technique | ID | Applicability |
+|-----------|-----|---------------|
+| User Execution | T1204.002 | Malicious markdown file |
+| Command and Scripting Interpreter | T1059.007 | JavaScript via nodeIntegration |
+| Command and Scripting Interpreter | T1059.006 | Python via REPL |
+| Command and Scripting Interpreter | T1059.004 | Bash via REPL |
+| Exploit Public-Facing Application | T1190 | XSS in preview |
+| Data Exfiltration Over Web Service | T1043 | PlantUML server |
+| File and Directory Discovery | T1083 | Path traversal |
+
+---
+
+## Trust Boundaries
+
+```
+┌─────────────────────────────────────────────────────────────────────┐
+│                         TRUST BOUNDARY MAP                          │
+├─────────────────────────────────────────────────────────────────────┤
+│                                                                     │
+│   ┌─────────────┐         ┌─────────────────────────────────────┐  │
+│   │   USER      │ ──────► │        APPLICATION                  │  │
+│   │ (Untrusted) │         │  ┌───────────┐  ┌───────────────┐  │  │
+│   └─────────────┘         │  │ Renderer  │  │ Main Process  │  │  │
+│                           │  │ (Sandbox) │  │ (Privileged)  │  │  │
+│                           │  └─────┬─────┘  └───────┬───────┘  │  │
+│                           │        │  IPC           │           │  │
+│                           │        ▼                ▼           │  │
+│                           │  ┌─────────────────────────────┐   │  │
+│                           │  │      File System            │   │  │
+│                           │  └─────────────────────────────┘   │  │
+│                           └─────────────────────────────────────┘  │
+│                                           │                        │
+│                                           ▼                        │
+│   ┌─────────────────────────────────────────────────────────────┐ │
+│   │                    EXTERNAL SERVICES                         │ │
+│   │  • PlantUML Server (www.plantuml.com)                       │ │
+│   │  • CDN (cdn.jsdelivr.net, cdnjs.cloudflare.com) [REMOVED]   │ │
+│   │  • External Tools (Pandoc, FFmpeg, LibreOffice)             │ │
+│   └─────────────────────────────────────────────────────────────┘ │
+│                                                                     │
+└─────────────────────────────────────────────────────────────────────┘
+```
+
+---
+
+## Business Impact Analysis
+
+### Successful Attack Consequences
+
+| Impact Category | Estimate |
+|-----------------|----------|
+| Data breach costs | $500,000 - $5,000,000+ |
+| Regulatory fines (GDPR) | Up to 4% annual revenue |
+| Reputation damage | Incalculable |
+| Business disruption | Hours to days |
+
+### Affected Assets
+- User documents and files
+- System credentials
+- Proprietary information in diagrams
+- Application integrity
+
+---
+
+## Remediation Priority
+
+### P0 - Immediate (24-48 hours)
+1. **CVE-MC-001**: Set `nodeIntegration: false`, `contextIsolation: true`
+2. **CVE-MC-002**: Remove or sandbox REPL code execution
+
+### P1 - Short-term (1-2 weeks)
+3. **CVE-MC-003**: Audit markdown extensions for XSS
+4. **CVE-MC-004**: Add path validation (✅ COMPLETED)
+5. **CVE-MC-005**: Strengthen CSP (✅ COMPLETED)
+
+### P2 - Medium-term (1 month)
+6. **CVE-MC-006**: Consistent window security settings
+7. **CVE-MC-007**: Add local PlantUML option or warning
+8. **CVE-MC-008**: Audit all BrowserWindow configurations
+
+### P3 - Long-term
+9. **CVE-MC-009**: Validate filenames for external tools
+10. **CVE-MC-010**: Pin dependency versions, add scanning
+
+---
+
+## Conclusion
+
+The MarkdownConverter application has a **HIGH RISK** threat profile due to the combination of:
+- Untrusted content rendering (markdown preview)
+- Direct system access (nodeIntegration)
+- Code execution capability (REPL)
+
+**Immediate action required on P0 items to reduce attack surface.**
+
+The fixes applied in this session (CSP, path traversal, UI accessibility) have reduced the risk profile, but the critical nodeIntegration issue requires significant refactoring.

.security-hardening/state.json

@@ -0,0 +1,27 @@
+{
+  "target": "MarkdownConverter Electron Application",
+  "status": "in_progress",
+  "depth": "comprehensive",
+  "compliance_frameworks": ["owasp"],
+  "current_step": 3,
+  "current_phase": 1,
+  "completed_steps": ["vulnerability-scan", "threat-modeling"],
+  "files_created": ["01-vulnerability-scan.md", "02-threat-model.md"],
+  "started_at": "2026-03-15T00:09:00.000Z",
+  "last_updated": "2026-03-15T00:25:00.000Z",
+  "findings_summary": {
+    "critical": 2,
+    "high": 3,
+    "medium": 3,
+    "low": 2,
+    "total": 10
+  },
+  "fixes_applied": {
+    "csp_external_cdns_removed": true,
+    "path_traversal_protection_added": true,
+    "aria_labels_added": true,
+    "focus_visible_styles_added": true,
+    "tab_close_button_resized": true,
+    "duplicate_font_size_fixed": true
+  }
+}

.ui-design/reviews/full-ui-review_20260315.md

@@ -0,0 +1,522 @@
+# Comprehensive UI Design Review - MarkdownConverter Electron Application
+
+## Executive Summary
+
+This review covers the UI design of the MarkdownConverter Electron application, analyzing visual design, usability, code quality, and performance across all UI files. The application has a solid foundation but has several areas requiring attention.
+
+---
+
+## 1. Visual Design Review
+
+### 1.1 Spacing & Layout Consistency
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Major** | Inconsistent padding values across files | Multiple CSS files | Standardize to 4px/8px base scale |
+| **Major** | Multiple reset declarations | `styles.css:1-5`, `styles-modern.css:42-47` | Consolidate resets into single file |
+| **Minor** | Tab padding varies between themes | `styles.css:36`, `styles-modern.css:101` | Use CSS variables for consistent padding |
+| **Minor** | Container padding inconsistency | `styles.css:17-21`, `styles-modern.css:63-69` | Define single container style |
+
+**Code Example - Duplicate Reset:**
+
+```css
+/* styles.css:1-5 */
+* {
+    margin: 0;
+    padding: 0;
+    box-sizing: border-box;
+}
+
+/* styles-modern.css:42-47 - DUPLICATE */
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
+```
+
+**Fix Recommendation:**
+```css
+/* Create a single base.css or remove from styles-modern.css */
+/* Use CSS variables for spacing scale */
+:root {
+  --space-1: 4px;
+  --space-2: 8px;
+  --space-3: 12px;
+  --space-4: 16px;
+  --space-5: 24px;
+  --space-6: 32px;
+}
+```
+
+### 1.2 Typography Consistency
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Major** | Font-family declared multiple times with different fallbacks | `styles.css:8`, `styles-modern.css:50`, `styles-concreteinfo.css:32` | Standardize font stack |
+| **Major** | Duplicate font-size declarations | `styles.css:228-230` | Remove duplicate |
+| **Minor** | Inconsistent line-height values | Multiple files | Create type scale variables |
+
+**Code Example - Duplicate font-size:**
+```css
+/* styles.css:226-230 */
+.preview-content {
+    max-width: none;
+    margin: 0;
+    padding: 20px 24px 24px 24px;
+    line-height: 1.6;
+    font-size: 15px;
+    font-size: 14px;  /* DUPLICATE - overwrites previous */
+}
+```
+
+**Fix Recommendation:**
+```css
+/* styles.css - Remove duplicate */
+.preview-content {
+    font-size: 14px;  /* Keep only one */
+    line-height: 1.6;
+}
+```
+
+### 1.3 Color Usage and Contrast Accessibility
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Critical** | Hardcoded colors instead of CSS variables | `styles.css:27-29`, `styles.css:37-38`, etc. | Use CSS custom properties |
+| **Major** | Inconsistent gray scale definitions | Multiple files define different grays | Consolidate to single palette |
+| **Minor** | Some contrast ratios may be insufficient | Status bar text colors | Verify WCAG 2.1 AA compliance |
+
+**Code Example - Hardcoded colors:**
+```css
+/* styles.css:27-29 */
+.tab-bar {
+    background: #f0f0f0;  /* Should use var(--gray-100) */
+    border-bottom: 1px solid #ddd;  /* Should use var(--gray-300) */
+}
+```
+
+**Fix Recommendation:**
+```css
+/* Use the existing palette from styles-modern.css */
+.tab-bar {
+    background: var(--gray-100, #f3f4f6);
+    border-bottom: 1px solid var(--gray-300, #d1d5db);
+}
+```
+
+### 1.4 Dark Mode Support Quality
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Major** | Dark theme selectors inconsistent | `styles.css` uses `body.theme-dark`, `styles-sidebar.css:108` uses `body[class*="dark"]` | Standardize selector pattern |
+| **Minor** | Missing dark theme support for some components | `.breadcrumb-bar`, command palette | Add dark mode variants |
+| **Suggestion** | Repetitive dark theme declarations | `styles-concreteinfo.css:362-425` | Use CSS custom properties for theming |
+
+**Code Example - Inconsistent selectors:**
+```css
+/* styles.css */
+body.theme-dark .tab-bar { ... }
+
+/* styles-sidebar.css */
+body[class*="dark"] .sidebar-icons { ... }
+```
+
+**Fix Recommendation:**
+```css
+/* Choose one pattern and apply consistently */
+/* Option 1: Class-based (recommended) */
+body.theme-dark .tab-bar,
+body.theme-dark .sidebar-icons { ... }
+
+/* Option 2: Attribute-based */
+body[data-theme="dark"] .tab-bar { ... }
+```
+
+---
+
+## 2. Usability Review
+
+### 2.1 Clickable/Tappable Areas
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Critical** | Tab close button too small (16x16px) | `styles.css:62-77` | Increase to minimum 24x24px |
+| **Major** | Sidebar icons at minimum size | `styles-sidebar.css:35-47` (36x36px) | Consider 40-44px for better touch |
+| **Minor** | Toolbar buttons at edge of minimum | `styles.css:120-131` (32x32px) | Acceptable for mouse, small for touch |
+
+**Code Example - Small close button:**
+```css
+/* styles.css:62-77 */
+.tab-close {
+    width: 16px;   /* TOO SMALL - below 24px minimum */
+    height: 16px;  /* TOO SMALL */
+}
+```
+
+**Fix Recommendation:**
+```css
+.tab-close {
+    width: 24px;
+    height: 24px;
+    border-radius: 4px;
+}
+
+/* Add touch-friendly hit area */
+.tab-close::before {
+    content: '';
+    position: absolute;
+    top: -4px;
+    left: -4px;
+    right: -4px;
+    bottom: -4px;
+}
+```
+
+### 2.2 Hover/Focus States
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Critical** | Missing focus-visible styles | All interactive elements | Add :focus-visible for keyboard navigation |
+| **Major** | No focus indicators on toolbar buttons | `styles.css:133-140` | Add visible focus ring |
+| **Minor** | Inconsistent hover transitions | Various components | Standardize transition duration |
+
+**Code Example - Missing focus styles:**
+```css
+/* styles.css:120-131 - No focus state */
+.toolbar button {
+    /* ... no focus style */
+}
+
+.toolbar button:hover {
+    background: #e0e0e0;
+    border-color: #ccc;
+}
+```
+
+**Fix Recommendation:**
+```css
+.toolbar button:focus-visible {
+    outline: 2px solid var(--primary-dark, #5661b3);
+    outline-offset: 2px;
+}
+
+.toolbar button:hover {
+    background: #e0e0e0;
+    border-color: #ccc;
+}
+```
+
+### 2.3 Loading and Error State Handling
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Major** | Generic error message without styling | `renderer.js:384-386`, `renderer.js:508-511` | Create styled error components |
+| **Minor** | No loading indicators for async operations | Sidebar panels | Add skeleton loaders or spinners |
+| **Minor** | `git-loading` class exists but minimal styling | `styles-sidebar.css:227` | Enhance with animation |
+
+**Code Example - Plain error display:**
+```javascript
+// renderer.js:384-386
+preview.innerHTML = '<p style="color: red; padding: 20px;">Error: Required libraries...';
+// Inline styles should be in CSS
+```
+
+**Fix Recommendation:**
+```css
+/* Add to styles.css */
+.preview-error {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    padding: 40px 20px;
+    color: var(--ci-danger, #dc3545);
+    text-align: center;
+}
+
+.preview-error-icon {
+    font-size: 48px;
+    margin-bottom: 16px;
+}
+```
+
+### 2.4 Accessibility (ARIA, Semantic HTML)
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Critical** | Buttons without accessible labels | `index.html:31` (tab close), `index.html:33` (new tab) | Add aria-label |
+| **Critical** | SVG icons lack aria-hidden | All toolbar buttons | Add aria-hidden="true" |
+| **Major** | Missing role attributes on tabs | `index.html:29-33` | Add role="tablist", role="tab" |
+| **Major** | No skip links | `index.html` | Add skip to main content link |
+| **Minor** | Dialog missing aria-modal | Export dialogs | Add aria-modal="true" |
+
+**Code Example - Missing accessibility attributes:**
+```html
+<!-- index.html:31 - Current -->
+<button class="tab-close" title="Close tab">x</button>
+
+<!-- index.html:33 - Current -->
+<button class="new-tab-button" id="new-tab-btn" title="New tab">+</button>
+```
+
+**Fix Recommendation:**
+```html
+<!-- Improved with ARIA -->
+<div class="tab-bar" id="tab-bar" role="tablist" aria-label="Document tabs">
+    <div class="tab active" data-tab-id="1" role="tab" aria-selected="true" aria-controls="tab-content-1">
+        <span class="tab-title">Untitled</span>
+        <button class="tab-close" aria-label="Close tab" title="Close tab">×</button>
+    </div>
+    <button class="new-tab-button" id="new-tab-btn" aria-label="Create new tab" title="New tab">+</button>
+</div>
+
+<!-- SVG icons should have aria-hidden -->
+<button id="btn-bold" title="Bold (Ctrl+B)" aria-label="Bold">
+    <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true">
+        ...
+    </svg>
+</button>
+```
+
+### 2.5 Keyboard Navigation
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Major** | Tab order may skip sidebar icons | Sidebar panel | Verify logical tab order |
+| **Minor** | No escape key handling for dialogs | Export dialogs | Add escape to close |
+| **Minor** | Find dialog lacks full keyboard support | `renderer.js:804-866` | Add Ctrl+F shortcut hint |
+
+---
+
+## 3. Code Quality Review
+
+### 3.1 CSS Organization & Naming
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Major** | No clear CSS architecture | All CSS files | Adopt BEM or similar methodology |
+| **Major** | Overly generic class names | `.pane`, `.tab`, `.container` | Use more specific naming |
+| **Minor** | Mixed naming conventions | camelCase (`tabBar`), kebab-case (`tab-bar`) | Standardize to kebab-case |
+| **Minor** | Magic numbers | Various pixel values | Replace with spacing variables |
+
+### 3.2 CSS Specificity Issues
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Major** | Excessive use of `!important` | `styles.css:14` | Restructure to avoid |
+| **Major** | Deep selector nesting | Dark theme selectors | Flatten and use CSS variables |
+| **Minor** | ID selectors for styling | `styles.css:233-247` | Prefer class selectors |
+
+**Code Example - Problematic specificity:**
+```css
+/* styles.css:14 - Avoid !important */
+.hidden {
+    display: none !important;
+}
+
+/* styles.css:397-431 - Deep nesting */
+body.theme-dark #preview h1,
+body.theme-dark [id^="preview-"] h1,
+body.theme-dark .preview-content h1 {
+    color: #c9d1d9;
+    border-bottom-color: #21262d;
+}
+```
+
+**Fix Recommendation:**
+```css
+/* Use utility class pattern */
+[hidden] { display: none; }
+
+/* Use CSS custom properties for theming */
+.preview-content h1 {
+    color: var(--text-primary);
+    border-bottom-color: var(--border-color);
+}
+
+/* Theme applies variables */
+body.theme-dark {
+    --text-primary: #c9d1d9;
+    --border-color: #21262d;
+}
+```
+
+### 3.3 Reusable Style Definitions
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Major** | Repeated button styles | Multiple files | Create button component classes |
+| **Major** | Dialog styles duplicated | Export, batch, print preview dialogs | Create modal component |
+| **Minor** | Similar form field styles scattered | Export dialog inputs | Create form component |
+
+**Code Example - Duplicated button styles:**
+```css
+/* styles.css */
+.toolbar button { /* button styles */ }
+.tab-close { /* button styles */ }
+.new-tab-button { /* button styles */ }
+#export-dialog-close { /* button styles */ }
+
+/* styles-sidebar.css */
+.sidebar-icon { /* similar button styles */ }
+.sidebar-panel-close { /* similar button styles */ }
+```
+
+**Fix Recommendation:**
+```css
+/* Create button component system */
+.btn {
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    border: none;
+    cursor: pointer;
+    transition: all var(--transition-fast);
+}
+
+.btn--icon {
+    width: 32px;
+    height: 32px;
+    border-radius: var(--radius-md);
+}
+
+.btn--close {
+    font-size: 14px;
+    font-weight: bold;
+    border-radius: var(--radius-sm);
+}
+```
+
+### 3.4 Documentation
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Minor** | Limited CSS documentation | All CSS files | Add section comments |
+| **Minor** | No component documentation | Sidebar components | Add JSDoc-style comments |
+| **Suggestion** | No design tokens documentation | CSS variables | Create tokens documentation |
+
+---
+
+## 4. Performance Review
+
+### 4.1 CSS Optimization
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Major** | Large CSS files (105KB main, 78KB modern) | `styles.css`, `styles-modern.css` | Split into smaller modules |
+| **Major** | Duplicate style definitions | Multiple files | Remove redundancies |
+| **Minor** | Unused styles likely present | Theme variations | Audit and remove unused |
+
+### 4.2 Asset Loading
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Major** | highlight.js CSS loaded synchronously | `index.html:14` | Load asynchronously or bundle |
+| **Minor** | Font files could be preloaded | `fonts.css` | Add preload links in HTML |
+| **Suggestion** | Consider CSS critical path | Above-the-fold styles | Inline critical CSS |
+
+**Code Example - Sync stylesheet loading:**
+```html
+<!-- index.html:14 - Blocks rendering -->
+<link rel="stylesheet" href="../node_modules/highlight.js/styles/default.css">
+```
+
+**Fix Recommendation:**
+```html
+<!-- Non-blocking load -->
+<link rel="stylesheet" href="../node_modules/highlight.js/styles/default.css" media="print" onload="this.media='all'">
+
+<!-- Or preload fonts -->
+<link rel="preload" href="../assets/fonts/Inter-Regular.woff2" as="font" type="font/woff2" crossorigin>
+```
+
+### 4.3 Animation Performance
+
+| Severity | Issue | Location | Recommendation |
+|----------|-------|----------|----------------|
+| **Minor** | Some transitions on expensive properties | `styles-modern.css:111-112` | Prefer transform/opacity |
+| **Suggestion** | Missing will-change hints | Complex animations | Add will-change for GPU hints |
+
+---
+
+## 5. Component-Specific Issues
+
+### 5.1 Tab System
+
+| File | Issues |
+|------|--------|
+| `styles.css:23-97` | Inconsistent active state styling, small close button |
+| `renderer.js:88-346` | Tab content created via innerHTML (XSS risk) |
+
+### 5.2 Sidebar
+
+| File | Issues |
+|------|--------|
+| `styles-sidebar.css` | Good structure but missing focus states |
+| `sidebar-manager.js` | Clean implementation, needs ARIA |
+
+### 5.3 Export Dialogs
+
+| File | Issues |
+|------|--------|
+| `styles.css:1060-1355` | Monolithic, should be component |
+| `index.html:171-331` | Complex nested structure needs semantic HTML |
+
+### 5.4 Welcome Screen
+
+| File | Issues |
+|------|--------|
+| `styles-welcome.css` | Minimal styles, good foundation |
+| Missing hover states for keyboard focus | Add :focus-visible |
+
+---
+
+## 6. Prioritized Fix Recommendations
+
+### Critical (Immediate)
+
+1. **Add missing ARIA attributes** to all interactive elements
+2. **Increase tab close button size** to minimum 24x24px
+3. **Add focus-visible styles** for keyboard navigation
+4. **Fix duplicate font-size declaration** in `.preview-content`
+
+### Major (Next Sprint)
+
+1. **Consolidate CSS resets** into single location
+2. **Create button component system** with variants
+3. **Standardize dark theme selectors** across all files
+4. **Replace hardcoded colors** with CSS variables
+5. **Create modal/dialog component** to reduce duplication
+
+### Minor (Future)
+
+1. **Document CSS architecture** and naming conventions
+2. **Audit and remove unused styles**
+3. **Add loading state components** (skeletons, spinners)
+4. **Implement CSS module splitting** for better performance
+
+---
+
+## 7. Summary Statistics
+
+| Category | Critical | Major | Minor | Suggestions |
+|----------|----------|-------|-------|-------------|
+| Visual Design | 1 | 5 | 4 | 1 |
+| Usability | 3 | 4 | 4 | 0 |
+| Code Quality | 0 | 6 | 4 | 1 |
+| Performance | 0 | 3 | 2 | 2 |
+| **Total** | **4** | **18** | **14** | **4** |
+
+---
+
+## Conclusion
+
+The MarkdownConverter application has a functional UI with good visual variety through its theme system. However, there are significant opportunities for improvement in:
+
+1. **Accessibility** - Critical for users with disabilities
+2. **Code organization** - Reduce CSS duplication and improve maintainability
+3. **Component consistency** - Standardize interactive element sizing and states
+4. **Performance** - Optimize CSS loading and reduce bundle size
+
+Addressing the Critical and Major issues will significantly improve both user experience and code maintainability.

.ui-design/reviews/review_state.json

@@ -0,0 +1,17 @@
+{
+  "review_id": "full-ui-review_20260315",
+  "target": "src/ (Entire UI Directory)",
+  "focus_areas": ["visual", "usability", "code", "performance"],
+  "context": "comprehensive",
+  "platform": "desktop",
+  "status": "complete",
+  "started_at": "2026-03-15T00:09:00.000Z",
+  "completed_at": "2026-03-15T00:12:00.000Z",
+  "issues_found": 40,
+  "severity_counts": {
+    "critical": 4,
+    "major": 18,
+    "minor": 14,
+    "suggestion": 4
+  }
+}

.vscode/launch.json

@@ -0,0 +1,48 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "Debug Main Process",
+      "type": "node",
+      "request": "launch",
+      "cwd": "${workspaceFolder}",
+      "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/electron",
+      "windows": {
+        "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/electron.cmd"
+      },
+      "args": ["."],
+      "outputCapture": "std",
+      "env": {
+        "NODE_ENV": "development"
+      }
+    },
+    {
+      "name": "Debug Renderer Process",
+      "type": "chrome",
+      "request": "attach",
+      "port": 9222,
+      "webRoot": "${workspaceFolder}/src",
+      "timeout": 30000
+    },
+    {
+      "name": "Debug Main + Renderer",
+      "type": "node",
+      "request": "launch",
+      "cwd": "${workspaceFolder}",
+      "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/electron",
+      "windows": {
+        "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/electron.cmd"
+      },
+      "args": [".", "--remote-debugging-port=9222"],
+      "outputCapture": "std",
+      "env": {
+        "NODE_ENV": "development"
+      },
+      "serverReadyAction": {
+        "pattern": "listening on port ([0-9]+)",
+        "uriFormat": "http://localhost:%s",
+        "action": "debugWithChrome"
+      }
+    }
+  ]
+}

AGENTS.md

@@ -0,0 +1,25 @@
+# Repository Guidelines
+
+## Project Structure & Module Organization
+Core application code lives in `src/`. Use `src/main.js` for the Electron main process, `src/preload.js` for the preload bridge, and `src/renderer.js` plus `src/editor/`, `src/sidebar/`, `src/repl/`, and `src/utils/` for renderer-side features. Electron adapter code is in `src/adapters/electron/`. Reusable markdown/document templates live in `src/templates/`. Static assets and icons are in `assets/`. Tests are in `tests/`, and build output goes to `dist/`.
+
+## Build, Test, and Development Commands
+- `npm start`: launch the Electron app locally.
+- `npm test`: run the Jest suite once.
+- `npm run test:watch`: rerun tests during local development.
+- `npm run test:coverage`: generate coverage output.
+- `npm run lint` / `npm run lint:fix`: check or fix ESLint issues in `src` and `tests`.
+- `npm run format` / `npm run format:check`: apply or verify Prettier formatting.
+- `npm run build:linux`, `npm run build:win`, `npm run build:mac`: create platform packages with `electron-builder`.
+
+## Coding Style & Naming Conventions
+This repo uses Prettier and ESLint. Follow `.prettierrc`: 2-space indentation, single quotes, semicolons, trailing commas where valid in ES5, and a 100-character line width. Prefer `camelCase` for variables/functions, `PascalCase` for classes, and kebab-case for file names only when already established. Keep module boundaries clear: UI logic in renderer modules, OS/file-system work behind Electron IPC and adapters.
+
+## Testing Guidelines
+Tests use Jest with `jest-environment-jsdom`. Add new tests under `tests/` with `*.test.js` names, mirroring the feature area when possible, for example `tests/sidebar.test.js` or `tests/print-preview.test.js`. Update or add regression tests for renderer behavior, preload APIs, and utility helpers when fixing bugs. Run `npm test` before opening a PR; use `npm run test:coverage` for larger refactors.
+
+## Commit & Pull Request Guidelines
+Recent history follows Conventional Commit prefixes such as `feat:`, `fix:`, and `refactor:`. Keep subjects short and imperative, for example `fix: guard modal cleanup on close`. PRs should describe the user-visible change, note test coverage, link any related issue, and include screenshots or GIFs for UI changes.
+
+## Security & Configuration Tips
+Do not bypass preload boundaries or introduce direct `eval`/dynamic code paths; ESLint already treats these as errors. Export and conversion features depend on external tools such as Pandoc, FFmpeg, ImageMagick, and LibreOffice, so document any new runtime dependency in `README.md` and packaging config.

CLAUDE.md

@@ -1,422 +1,103 @@
-# PanConverter - Claude Development Guide
+# CLAUDE.md — MarkdownConverter (master)
+
+> General code-quality, JavaScript, git, security, and testing standards are in the **global CLAUDE.md**. This file holds project- and branch-specific notes.
 
 ## Project Overview
 
-**PanConverter** is a cross-platform Markdown editor and converter powered by Pandoc, built with Electron. It provides professional-grade editing capabilities with comprehensive export options.
+Electron desktop app for Markdown editing and universal file conversion powered by Pandoc. Cross-platform (Win/macOS/Linux). Features: multi-tab editor with live preview, 25+ themes, PDF viewer/editor (merge/split/compress/rotate/watermark/password), export to 20+ formats (PDF/DOCX/ODT/EPUB/HTML/LaTeX/RTF/PPTX), batch conversion, syntax highlighting, diagram support (Mermaid), Git integration, and a plugin system.
 
-**Current Version**: v1.5.0
+- **Version:** 4.4.3
-**Author**: Amit Haridas (amit.wh@gmail.com)
+- **License:** MIT
-**License**: MIT
+- **App ID:** `com.concreteinfo.markdownconverter`
-**Repository**: https://github.com/amitwh/pan-converter
 
-## Architecture & Technology Stack
+## Branch Specifics
 
-### Core Technologies
+This is the **primary/release branch** — a vanilla JavaScript Electron app with no bundler or framework in the renderer. The renderer is a single large `renderer.js` (5,300+ lines) loaded directly via `src/index.html`. All UI is hand-rolled DOM manipulation.
-- **Electron** - Cross-platform desktop application framework
-- **Pandoc** - Universal document converter (required system dependency)
-- **marked** - Markdown parsing and rendering
-- **highlight.js** - Syntax highlighting
-- **KaTeX** - Mathematical expression rendering
-- **DOMPurify** - HTML sanitization
 
-### Application Structure
+## Architecture
-```
-src/
-├── main.js        # Electron main process, menu system, IPC handlers
-├── renderer.js    # TabManager class, multi-file editing, event handling
-├── index.html     # Application layout with tabbed interface
-└── styles.css     # Comprehensive styling with multi-theme support
 
-assets/
+### Main Process (`src/main.js` — 4,260 lines)
-└── icon.png       # Application icon
+Monolithic main process file. Contains all IPC handlers, Pandoc invocation, file operations, menu definitions (600+ lines), and window lifecycle. Key modules extracted:
+- `src/main/PDFOperations.js` — PDF manipulation via `pdf-lib` (merge, split, compress, rotate, delete, reorder, watermark, encrypt, decrypt, permissions)
+- `src/main/GitOperations.js` — Git status/stage/commit/log via `simple-git`
 
-package.json       # Dependencies and build configuration
+### Renderer (`src/renderer.js` — 5,361 lines)
-CLAUDE.md          # Development documentation for AI assistants
+Vanilla JS, no framework. Directly manipulates DOM. Loads CodeMirror 6 via `src/editor/codemirror-setup.js`. Uses `marked` + `highlight.js` + `DOMPurify` + `mermaid` for rendering. Lazy-loads sidebar panels, REPL, command palette, zen mode.
-```
+
+### Preload (`src/preload.js` — 448 lines)
+Exists as IPC bridge, but **`contextIsolation: false` and `nodeIntegration: true`** — the renderer has full Node access. Preload is effectively a thin passthrough.
+
+### Security Model
+- `contextIsolation: false` + `nodeIntegration: true` (legacy; the react-electron branch fixes this)
+- Pandoc invoked via `execFile` (not `exec`) to prevent shell injection
+- Path traversal protection: `validatePath()`, `resolveWritablePath()`, blocks sensitive system dirs
+- Permission handler only allows `clipboard-read`/`clipboard-write`
+- Rate limiter on conversions (2-second minimum interval)
+- File size limit: 50MB
+- Error message sanitization strips absolute paths
+
+### Plugin System (`src/plugins/`)
+Manifest-based discovery (`manifest.json`). Built-in `writing-studio` plugin with sprint/goal/snapshot management. Plugin API exposed via `src/plugins/plugin-api.js`.
+
+### Settings
+Custom JSON file store at `<userData>/settings.json` (NOT `electron-store` despite the dependency). Recent files at `<userData>/recent-files.json`.
+
+## System Dependencies
+
+| Dependency | Required | Notes |
+|---|---|---|
+| **Node.js** | >= 20 | Electron 41 bundles Node 20.x |
+| **Pandoc** | Yes (for exports) | Downloaded to `bin/<platform>/pandoc` via `scripts/download-tools.js` (v3.9.0.2). Falls back to system PATH. Must be present for DOCX/ODT/EPUB/LaTeX/PPTX export. |
+| **FFmpeg** | Bundled | `ffmpeg-static` npm package; `asarUnpacked` for packaged builds |
+| **MiKTeX / TeX Live** | Optional | For LaTeX PDF export; MiKTeX PATH injected on Windows automatically |
+| **ImageMagick** | Optional | Linux image conversion; listed as deb dependency |
+| **LibreOffice** | Optional | Enhanced document conversion; listed as deb dependency |
 
 ## Development Commands
 
-### Prerequisites
 ```bash
-# Install Node.js dependencies
+npm start                  # Launch Electron app (dev mode)
-npm install
+npm test                   # Jest test suite
-
+npm test:watch             # Jest in watch mode
-# Install Pandoc (required for export functionality)
+npm test:coverage          # Jest with coverage report
-# Ubuntu/Debian:
+npm run lint               # ESLint check (src + tests)
-sudo apt-get install pandoc
+npm run lint:fix           # ESLint auto-fix
-
+npm run format             # Prettier write
-# macOS:
+npm run format:check       # Prettier check only
-brew install pandoc
+npm run download-tools     # Download Pandoc binaries to bin/
-
+npm run generate-icons     # Generate app icons via sharp
-# Windows: Download from https://pandoc.org/installing.html
 ```
 
-### Running the Application
+## Build & Package
-```bash
-# Start development server
-npm start
 
-# Start with debugging
+**Tool:** `electron-builder` (v26.0.12), config inline in `package.json` (no separate config file).
-npm start --enable-logging
-```
 
-### Building & Packaging
+| Target | Platforms |
+|---|---|
+| `npm run build` | electron-builder (default platform) |
+| `npm run build:win` | Windows: NSIS installer + portable + zip (x64) |
+| `npm run build:mac` | macOS: default dmg |
+| `npm run build:linux` | Linux: deb + AppImage + snap |
+| `npm run dist` | Build without publish |
+| `npm run dist:all` | Build for all platforms |
 
-```bash
+**Bundled with builds:** Pandoc binary per platform. FFmpeg via `ffmpeg-static` (asarUnpacked). NSIS installer uses custom script at `scripts/nsis-installer.nsh`.
-# Generate application icons
-npm run generate-icons
 
-# Build for current platform
+**Output:** `dist/` directory.
-npm run build
 
-# Platform-specific builds
+**CI:** GitHub Actions workflows in `.github/workflows/` (ci.yml, release.yml).
-npm run build:win      # Windows
-npm run build:mac      # macOS
-npm run build:linux    # Linux (AppImage, .deb, .snap)
 
-# Build for all platforms
+## Project Conventions / Gotchas
-npm run dist:all
-```
 
-### Git Branch Management
+- **No bundler/transpilation.** The app uses vanilla CommonJS JavaScript. `src/main.js` is loaded directly by Electron. No webpack, no Vite, no TypeScript, no Babel.
-```bash
+- **Monolithic files.** `main.js` (4,260 lines) and `renderer.js` (5,361 lines) contain most logic. Not ideal but is the current state of this branch.
-# Switch to platform-specific branches
+- **CodeMirror 6** for the editor, configured in `src/editor/codemirror-setup.js`.
-git checkout linux    # Linux development
+- **PDF rendering** uses `pdfjs-dist`; **PDF manipulation** uses `pdf-lib` in the main process.
-git checkout macos     # macOS development  
+- **Renderer security is weak** — full Node access in renderer. Do NOT introduce new privileged renderer code without understanding this.
-git checkout windows   # Windows development
+- **Pandoc is external.** Must be installed separately or downloaded via `npm run download-tools`. HTML and built-in PDF export work without Pandoc; other formats require it.
-git checkout master    # Main development branch
+- **PDF export fallback chain:** xelatex -> pdflatex -> lualatex -> Electron built-in `printToPDF()`.
-
+- **ESLint flat config** (`eslint.config.js`) with ECMAScript 2022. Prettier with 2-space indent, single quotes, semicolons, 100-char width.
-# Update all branches with latest changes
+- **Tests:** Jest with jsdom environment, 15% coverage threshold. 24 test files in `tests/`.
-git checkout master
+- **File associations:** `.md`, `.markdown`, `.pdf` registered at install.
-git push origin master
+- **Single instance lock** enforced via `app.requestSingleInstanceLock()`.
-git checkout linux && git merge master && git push origin linux
+- **Adapters layer** (`src/adapters/`) abstracts file system operations for potential future non-Electron targets.
-git checkout macos && git merge master && git push origin macos
-git checkout windows && git merge master && git push origin windows
-```
-
-### Release Management
-```bash
-# Create and push release tag
-git tag v1.2.1 -m "Release message"
-git push origin v1.2.1
-
-# Create GitHub release with packages
-gh release create v1.2.1 --title "Title" --notes "Release notes" \
-  "dist/PanConverter-1.2.1.AppImage" \
-  "dist/pan-converter_1.2.1_amd64.deb" \
-  "dist/pan-converter_1.2.1_amd64.snap"
-```
-
-## Feature Implementation Guide
-
-### v1.5.0 Enhanced Features & Open Source Compatibility (Latest)
-
-#### 🔧 Export Function Fixes & Optional Advanced Options
-**Export Dialog Enhancement** (`src/index.html:125-133`, `src/renderer.js:960-985`)
-- Fixed export function issues after advanced export options integration
-- Added optional advanced export options via checkbox toggle (unchecked by default)
-- Basic export options always visible, advanced options hidden until enabled
-- Clean UI separation between simple and advanced export workflows
-
-#### 🏗️ Open Source Compatibility & Dependency Removal
-**Removed Proprietary Dependencies** (`src/main.js:430-450`, `package.json:32-37`)
-- Removed bundled Pandoc binaries - now requires system-installed Pandoc
-- Replaced proprietary XLSX dependency with open-source CSV export
-- Removed non-essential bundled binaries to ensure open-source compatibility
-- Updated export functions to use system Pandoc installation
-
-#### ✨ Advanced User Experience Features
-**Auto-Save System** (`src/renderer.js:445-484`)
-- Automatic saving every 30 seconds with visual indicators
-- Smooth slide-in animation for auto-save notifications
-- Prevents data loss during extended editing sessions
-- Integrated with file opening and tab creation workflows
-
-**Enhanced Document Statistics** (`src/renderer.js:385-444`)
-- Comprehensive statistics: words, characters, lines, paragraphs, sentences
-- Estimated reading time calculation (200 words per minute)
-- Real-time updates as user types
-- Professional presentation in status bar
-
-**Recent Files Management** (`src/main.js:69-114`, `src/renderer.js:487-512`)
-- Recent files menu with last 10 opened files
-- Persistent storage via localStorage and user data directory
-- Menu integration with File > Recent Files submenu
-- Clear recent files functionality with menu rebuild
-
-**Mathematical Expression Support** (`src/renderer.js:1099-1130`, `src/renderer.js:292-306`)
-- KaTeX integration for rendering mathematical expressions
-- Support for multiple delimiters: $$, $, \\[\\], \\(\\)
-- Real-time math rendering in preview pane
-- Fallback handling for missing KaTeX library
-
-### v1.4.0 Advanced Export & Batch Processing
-
-#### 🔧 Fixed File Association Support
-**File Loading Fix** (`src/main.js:385-390`, `src/renderer.js:485-486`)
-- Fixed timing issue with file association loading
-- Added proper `renderer-ready` event to ensure TabManager is initialized
-- Files now open correctly when double-clicked or opened via right-click menu
-- Command-line file arguments are properly handled on startup
-
-#### 🎛️ Advanced Export Options Dialog
-**Template & Metadata Support** (`src/main.js:247-357`, `src/index.html:117-212`)
-- Comprehensive export options dialog with professional UI
-- Template selection (default or custom template files)
-- Metadata fields (title, author, date, subject) with dynamic field addition
-- Document options: Table of Contents, section numbering, citations
-- PDF-specific options: Engine selection (XeLaTeX, PDFLaTeX, LuaLaTeX), custom margins
-- Bibliography support: .bib, .yaml, .json files with CSL styling
-- All export formats now use enhanced options dialog
-
-#### 📁 Batch File Conversion System
-**Multi-File Processing** (`src/main.js:179-186`, `src/main.js:559-690`)
-- New "Batch" menu for converting entire folders
-- Recursive folder processing with progress tracking
-- Support for all export formats with advanced options
-- Real-time progress bar and file-by-file status updates
-- Maintains folder structure in output directory
-- Error handling with completion statistics
-
-#### 🎨 Enhanced UI Components
-**Dialog System** (`src/styles.css:838-1361`)
-- Professional modal dialogs with backdrop and animations
-- Theme-aware styling for all new components
-- Responsive layouts with proper accessibility
-- Form validation and user feedback systems
-- Progress indicators for long-running operations
-
-### v1.3.x Tabbed Interface & Enhanced Features
-
-#### 🗂️ Tabbed Multi-File Support (v1.3.0)
-**TabManager Class** (`src/renderer.js`)
-- Complete tab management system for multiple files
-- Tab switching, creation, and closure
-- State preservation per tab (content, cursor position, scroll)
-- File path tracking for each tab
-- Keyboard shortcuts: `Ctrl/Cmd+T` (new tab), `Ctrl/Cmd+W` (close tab)
-
-#### 🎯 Enhanced PDF Export (v1.3.0)
-**Multi-Engine Fallback System** (`src/main.js:239-280`)
-- Primary: XeLaTeX with proper margins
-- Fallback 1: PDFLaTeX
-- Fallback 2: wkhtmltopdf
-- Automatic engine detection and switching
-
-#### 📁 File Association Support (v1.3.1)
-**OS Integration** (`src/main.js:452-498`, `package.json:50-65`)
-- Double-click .md files to open in PanConverter
-- Command-line argument handling
-- Pending file queue for startup loading
-
-#### 🎨 Typography & Spacing (v1.3.2-1.3.3)
-**Preview Enhancement** (`src/styles.css`)
-- Restored ideal text spacing from v1.0
-- Font sizes increased to 15px for better readability
-- Comprehensive selector coverage for legacy and new containers
-- Theme-aware typography for all content types
-
-### v1.2.1 Comprehensive Editor Enhancements
-
-#### ✨ Advanced Editor Features
-
-**Find & Replace System** (`src/renderer.js:200-350`)
-- Dialog-based interface with match highlighting
-- Forward/backward navigation through matches
-- Replace single or replace all functionality
-- Real-time match counting and status display
-- Escape key closes dialog
-
-**Line Numbers** (`src/renderer.js:450-500`, `src/styles.css:517-598`)
-- Toggle-able line numbers with toolbar button
-- Synchronized scrolling with editor content
-- Theme-aware styling for all supported themes
-- Dynamic line number generation based on content
-
-**Undo/Redo System** (`src/renderer.js:100-150`)
-- Stack-based state management for editor history
-- Keyboard shortcuts: `Ctrl/Cmd+Z` (undo), `Ctrl/Cmd+Shift+Z` (redo)
-- Intelligent state saving on text changes
-- Memory-efficient history management
-
-**Smart Auto-Indentation** (`src/renderer.js:350-400`)
-- Automatic list continuation on Enter key
-- Proper indentation handling for nested lists
-- Support for ordered and unordered lists
-- Intelligent whitespace management
-
-**Enhanced Keyboard Shortcuts** (`src/renderer.js:400-450`)
-- `Tab`/`Shift+Tab` for line indentation/outdentation
-- `Enter` for auto-continuing lists
-- `Ctrl/Cmd+F` for find & replace dialog
-- `Escape` for closing dialogs
-
-**Word/Character Count** (`src/renderer.js:500-530`)
-- Live counting displayed in status bar
-- Updates automatically as content changes
-- Word and character statistics
-
-#### 📤 Export & Conversion Features
-
-**PowerPoint Export** (`src/main.js:330-350`)
-- Convert markdown to PPTX presentations
-- Automatic slide-level formatting (`--slide-level=2`)
-- Smart presentation structure handling
-
-**Spreadsheet Export** (`src/main.js:370-457`)
-- Export markdown tables to Excel (XLSX/XLS) and ODS formats
-- Multi-table support with separate worksheets
-- Automatic table detection and parsing
-- Error handling for files without tables
-
-**Document Import** (`src/main.js:280-315`)
-- Import DOCX, ODT, RTF, HTML, PDF, PPTX, ODP files
-- Automatic conversion to markdown format
-- File dialog with appropriate filters
-- Success notifications and error handling
-
-**Table Creation Helper** (`src/renderer.js:600-650`)
-- Built-in table generator with row/column specification
-- Automatic markdown table formatting
-- Proper header separation and alignment
-
-#### 🎨 Interface & Theming
-
-**Multi-Theme Support** (`src/styles.css:214-598`)
-- Light, Dark, Solarized, Monokai, GitHub themes
-- Complete theming for all UI components
-- Theme-aware styling for new features (find dialog, line numbers)
-- Persistent theme selection with local storage
-
-**Enhanced UI Components** (`src/index.html:94-108`)
-- Find & replace dialog with modern styling
-- Toolbar buttons for all new features
-- Status bar with live statistics
-- Responsive layout with proper spacing
-
-## File Structure & Key Components
-
-### Main Process (`src/main.js`)
-- **Menu System**: Comprehensive menu with file operations, editing, conversion, view options, batch processing
-- **IPC Handlers**: Communication between main and renderer processes
-- **File Operations**: Open, save, import/export functionality with file association support
-- **Export System**: Advanced export with templates, metadata, and Pandoc integration
-- **Batch Processing**: Multi-file conversion with progress tracking and error handling
-- **Theme Management**: Persistent theme storage and application
-- **Spreadsheet Export**: Table extraction and XLSX generation
-- **About Dialog**: Application information and feature list
-
-### Renderer Process (`src/renderer.js`)
-- **Editor Initialization**: CodeMirror-like functionality with custom implementation
-- **TabManager System**: Multi-file editing with state management
-- **Find & Replace Engine**: Search algorithms with regex support
-- **Undo/Redo Manager**: History stack management
-- **Auto-indentation Logic**: Smart list continuation
-- **Live Preview**: Real-time markdown rendering with DOMPurify
-- **Export Dialog Management**: Advanced options collection and validation
-- **Batch Conversion Interface**: Folder selection, progress tracking, and user feedback
-- **Event Handling**: Keyboard shortcuts and UI interactions
-- **Statistics Tracking**: Word/character counting
-
-### Styling (`src/styles.css`)
-- **Base Styles**: Application layout and typography
-- **Component Styles**: Toolbar, editor, preview, dialogs
-- **Theme Implementations**: Complete styling for all themes
-- **Responsive Design**: Flexible layouts and proper spacing
-- **Animation Support**: Smooth transitions and hover effects
-
-### HTML Structure (`src/index.html`)
-- **Toolbar**: Feature buttons with SVG icons
-- **Tab Bar**: Multi-file navigation with close buttons
-- **Find Dialog**: Search and replace interface
-- **Export Options Dialog**: Advanced export configuration with templates and metadata
-- **Batch Conversion Dialog**: Folder selection and conversion progress
-- **Editor Container**: Line numbers and text editor with tab content management
-- **Preview Pane**: Rendered markdown display
-- **Status Bar**: Statistics and application status
-
-## Testing & Quality Assurance
-
-### Manual Testing Checklist
-- [ ] All keyboard shortcuts work correctly
-- [ ] Find & replace functions properly with edge cases
-- [ ] Line numbers sync correctly with content
-- [ ] Undo/redo preserves cursor position
-- [ ] Auto-indentation works with various list types
-- [ ] File association loading (double-click .md files)
-- [ ] Export options dialog with templates and metadata
-- [ ] Batch conversion with progress tracking
-- [ ] All themes render correctly for new components
-- [ ] Export functions work with various document formats
-- [ ] Table creation and export functionality
-- [ ] Cross-platform compatibility
-
-### Known Issues & Limitations
-- AppImage may require `--no-sandbox` flag on some Linux systems
-- Large files (>1MB) may cause performance issues
-- Windows/Mac builds require platform-specific environments
-- Pandoc must be installed separately for export functionality
-
-## Deployment & Distribution
-
-### Release Packages
-- **Linux AppImage**: Universal Linux package (self-contained)
-- **Debian Package**: `.deb` for Ubuntu/Debian systems
-- **Snap Package**: Universal Linux package via Snap Store
-- **Future**: Windows `.exe` and macOS `.dmg` packages
-
-### Release Process
-1. Update version in `package.json`, `src/main.js`, and `README.md`
-2. Commit changes and push to all platform branches
-3. Build platform-specific packages
-4. Create Git tag and GitHub release
-5. Upload packages to GitHub release
-6. Update documentation and announce release
-
-## Contributing Guidelines
-
-### Code Style
-- Use consistent indentation (2 spaces)
-- Follow JavaScript ES6+ standards
-- Comment complex functionality
-- Maintain separation between main and renderer processes
-- Use descriptive variable and function names
-
-### Adding New Features
-1. Plan feature implementation and UI integration
-2. Update relevant files (main.js, renderer.js, styles.css)
-3. Test across all supported themes
-4. Update documentation and README
-5. Test on multiple platforms if possible
-6. Submit pull request with detailed description
-
-### Bug Reporting
-- Include steps to reproduce
-- Specify platform and version information
-- Attach relevant screenshots or error logs
-- Check existing issues before creating new ones
-
-## Future Roadmap
-
-### Planned Features
-- [ ] Collaborative editing capabilities
-- [ ] Plugin system for extensions
-- [ ] Advanced markdown extensions (math, diagrams)
-- [ ] Cloud synchronization options
-- [ ] Mobile companion app
-- [ ] Advanced export templates
-- [ ] Spell check and grammar checking
-- [ ] Version control integration
-
-### Technical Improvements
-- [ ] Performance optimization for large files
-- [ ] Memory usage optimization
-- [ ] Startup time improvements
-- [ ] Better error handling and user feedback
-- [ ] Automated testing suite
-- [ ] Continuous integration/deployment
-
----
-
-**Last Updated**: September 15, 2025
-**Claude Assistant**: Development completed for v1.5.0 with optional advanced export options, removed proprietary dependencies for open-source compatibility, enhanced auto-save functionality, comprehensive document statistics, recent files management, and mathematical expression support using KaTeX.

PUSH_INSTRUCTIONS.md

@@ -1,95 +1,12 @@
-# Push Instructions for Pan Converter
+# Test Double-Click File Opening
 
-## Prerequisites
+This is a test file to verify double-click functionality.
-1. Create a new repository on GitHub: https://github.com/new
-   - Repository name: `pan-converter`
-   - Keep it empty (no README, .gitignore, or license)
-   - Make it public or private as desired
 
-2. Set up authentication:
+## Features to Test
-   - **Option A - SSH Key** (Recommended):
+- File should load automatically
-     ```bash
+- Content should display in editor
-     # Check if you have SSH key
+- Tab should show filename
-     ls -la ~/.ssh/id_rsa.pub
+- Preview should render markdown
-     
-     # If not, generate one:
-     ssh-keygen -t rsa -b 4096 -C "your_email@example.com"
-     
-     # Add to GitHub: Settings > SSH and GPG keys > New SSH key
-     cat ~/.ssh/id_rsa.pub
-     ```
-   
-   - **Option B - Personal Access Token**:
-     - Go to GitHub Settings > Developer settings > Personal access tokens
-     - Generate new token with 'repo' scope
-     - Save the token securely
 
-## Push Commands
+**This text should be bold**
-
+*This text should be italic*
-### Using SSH (Recommended)
-```bash
-# Set SSH remote
-git remote set-url origin git@github.com:amitwh/pan-converter.git
-
-# Push all branches
-git push -u origin master
-git push origin linux
-git push origin macos
-git push origin windows
-```
-
-### Using HTTPS with Token
-```bash
-# Set HTTPS remote
-git remote set-url origin https://github.com/amitwh/pan-converter.git
-
-# Push all branches (you'll be prompted for username and token)
-git push -u origin master
-git push origin linux
-git push origin macos
-git push origin windows
-
-# When prompted:
-# Username: amitwh
-# Password: [paste your Personal Access Token]
-```
-
-### Using GitHub CLI (if installed)
-```bash
-# Login to GitHub CLI
-gh auth login
-
-# Create repo and push
-gh repo create pan-converter --public --source=. --remote=origin --push
-```
-
-## Automated Script
-```bash
-# Run the provided script
-./push-to-github.sh
-```
-
-## Verify Success
-After pushing, verify at: https://github.com/amitwh/pan-converter
-
-You should see:
-- 4 branches (master, linux, macos, windows)
-- All project files
-- Complete commit history
-
-## Troubleshooting
-
-### Authentication Failed
-- For SSH: Ensure your SSH key is added to GitHub
-- For HTTPS: Use Personal Access Token, not password
-- Check token has 'repo' scope
-
-### Repository Not Found
-- Ensure repository exists on GitHub
-- Check spelling: `pan-converter`
-- Verify you're logged into the correct GitHub account
-
-### Permission Denied
-- Check repository ownership
-- Ensure you have write access
-- Verify authentication method is correct

README.md

@@ -1,160 +1,156 @@
-# PanConverter
+# MarkdownConverter
 
-A cross-platform Markdown editor and converter powered by Pandoc.
+A powerful cross-platform Markdown editor and document converter powered by Pandoc, built with Electron. 100% open-source with no proprietary dependencies.
-
-![PanConverter](assets/icon.png)
 
 ## Features
 
-### ✨ Advanced Markdown Editor
+### Markdown Editor
-- 🗂️ **Tabbed Interface** - Work with multiple files simultaneously in separate tabs
+<img width="1920" height="1032" alt="image" src="https://github.com/user-attachments/assets/5f53ba94-7663-47c3-b12b-b7b8bd2645aa" />
-- 📝 **Rich Text Editor** - Full-featured editor with syntax highlighting and comprehensive toolbar
+- **Multi-tab editing** - Work on multiple files simultaneously
-- 🔍 **Find & Replace** - Powerful search and replace with match highlighting and navigation
+- **Live preview** - Real-time markdown rendering with syntax highlighting
-- 🔢 **Line Numbers** - Toggle line numbers for easier code editing and navigation
+- **Dynamic splitter** - Drag to resize editor and preview panes
-- ↩️ **Smart Auto-Indentation** - Automatic list continuation and intelligent indentation
+- **25+ themes** - Light and dark themes including Atom One Light, Dracula, Nord, Sepia, and more
-- ⏪ **Undo/Redo** - Full undo/redo support with keyboard shortcuts
+- **Find & Replace** - Search and replace with regex support
-- ⌨️ **Advanced Shortcuts** - Tab indentation, line selection, and smart text formatting
+- **Line numbers** - Toggle line numbers in the editor
-- 📂 **File Association Support** - Open markdown files directly from file manager
+- **Auto-save** - Automatic saving every 30 seconds
+- **Math support** - KaTeX integration for mathematical expressions
 
-### 🎨 Themes & Interface
+### PDF Viewer & Editor
-- 👁️ **Live Preview** - See your markdown rendered in real-time with synchronized scrolling
+<img width="1920" height="1032" alt="image" src="https://github.com/user-attachments/assets/f10f62be-af3d-496e-81df-37ab4f91abfd" />
-- 🎨 **Multiple Themes** - Choose from Light, Dark, Solarized, Monokai, or GitHub themes
-- 💾 **Auto-Save** - Never lose your work with automatic saving every 30 seconds
-- 📊 **Enhanced Statistics** - Detailed document statistics including word count, character count, lines, paragraphs, sentences, and estimated reading time
-- 🕒 **Recent Files** - Quick access to recently opened files via File menu
-- 🧮 **Math Support** - Render mathematical expressions using KaTeX (supports $$, $, \\[\\], \\(\\) delimiters)
 
-### 📤 Export & Conversion
+- **Built-in PDF viewer** - Open and view PDF files directly in the app
-- 📄 **Enhanced PDF Export** - Robust PDF generation with multiple LaTeX engine fallbacks (XeLaTeX, PDFLaTeX, wkhtmltopdf)
+- **Page navigation** - Navigate pages with keyboard or buttons
-- 📄 **Document Export** - Convert to HTML, DOCX, LaTeX, RTF, ODT, EPUB, PowerPoint (PPTX), and OpenDocument Presentation (ODP)
+- **Zoom controls** - Zoom in/out, fit to width, fit to page
-- 📊 **Spreadsheet Export** - Export markdown tables to CSV format for compatibility with any spreadsheet application
+- **Rotation** - Rotate pages left or right
-- 📥 **Document Import** - Import DOCX, ODT, RTF, HTML, PDF, and presentation files to markdown
+- **PDF Editor tools**:
-- 📋 **Table Creation Helper** - Built-in table generator for easy markdown table creation
+  - Merge multiple PDFs
+  - Split PDFs by page range
+  - Compress PDFs
+  - Rotate pages
+  - Delete pages
+  - Reorder pages
+  - Add watermarks
+  - Password protection
+  - Remove passwords
+  - Set permissions
 
-### 🖥️ Platform Support
+### Export Options
-- **Cross-Platform** - Works seamlessly on Windows, macOS, and Linux
+- **PDF** - Export to PDF with customizable page sizes and orientation
+- **DOCX** - Standard and Enhanced (template-based) Word export
+- **ODT** - OpenDocument format
+- **HTML** - Web-ready HTML export
+- **PowerPoint** - PPTX presentation export
+- **EPUB** - E-book format
+- **LaTeX** - Academic document format
+- **RTF** - Rich Text Format
+
+### Advanced Features
+- **Custom headers & footers** - Add headers/footers to exports with dynamic fields
+- **Page size configuration** - A3, A4, A5, B4, B5, Letter, Legal, Tabloid, or custom sizes
+- **Batch conversion** - Convert entire folders of markdown files
+- **ASCII Art Generator** - Create text banners and diagrams
+- **Word templates** - Use custom Word templates for enhanced exports
+- **Import documents** - Import from 30+ formats (DOCX, PDF, HTML, etc.)
 
 ## Installation
 
 ### Prerequisites
-- [Pandoc](https://pandoc.org/installing.html) must be installed for export functionality
+- [Node.js](https://nodejs.org/) (v16 or later)
-  - **Ubuntu/Debian**: `sudo apt-get install pandoc`
+- [Pandoc](https://pandoc.org/installing.html) (required for export functionality)
-  - **macOS**: `brew install pandoc`
-  - **Windows**: Download installer from Pandoc website
 
-### PDF Export Requirements
+### Install Dependencies
-For optimal PDF export, install a LaTeX engine (recommended):
-- **Ubuntu/Debian**: `sudo apt-get install texlive-xetex texlive-latex-base`
-- **macOS**: `brew install --cask mactex`
-- **Windows**: Install MiKTeX or TeX Live
-- **Alternative**: `sudo apt-get install wkhtmltopdf` (fallback option)
-
-### Download
-Download the latest release for your platform from the [Releases](https://github.com/amitwh/pan-converter/releases) page.
-
-#### Linux
-- **AppImage**: `PanConverter-1.5.0.AppImage` (universal, may require `--no-sandbox` flag)
-- **Debian Package**: `pan-converter_1.5.6_amd64.deb`
-- **Snap Package**: `pan-converter_1.5.6_amd64.snap`
-
-### Install from Source
 ```bash
-git clone https://github.com/amitwh/pan-converter.git
-cd pan-converter
 npm install
+```
+
+### Run the Application
+```bash
 npm start
 ```
 
-## Usage
+### Build for Distribution
+```bash
+# Windows
+npm run build:win
 
-### Basic Workflow
+# macOS
-1. **Write** - Use the editor to write your Markdown content
+npm run build:mac
-2. **Preview** - Toggle the preview pane to see rendered output
-3. **Theme** - Choose your preferred theme from the View menu
-4. **Export** - Export your document to various formats
 
-### Export Options
+# Linux
-- **Documents**: HTML, PDF, DOCX, LaTeX, RTF, ODT, EPUB
+npm run build:linux
-- **Presentations**: PowerPoint (PPTX), OpenDocument Presentation (ODP)
+```
-- **Spreadsheets**: CSV format for tables (compatible with Excel, LibreOffice, Google Sheets)
-- **Advanced Export Options**: Optional template support, metadata insertion, table of contents, section numbering, and PDF-specific settings
-- **Batch Conversion**: Convert entire folders of markdown files with progress tracking
-
-### Import & Conversion
-- **Import Documents**: Convert DOCX, ODT, RTF, HTML, PDF, and presentation files to Markdown
-- **Cross-Format Conversion**: Convert current file between multiple formats
-- **Smart Presentation Handling**: Automatic slide-level formatting for PPTX/ODP exports
-
-### Table Creation
-- Click the table button in the toolbar
-- Specify number of rows and columns
-- Automatically generates properly formatted Markdown tables
 
 ## Keyboard Shortcuts
 
-### File Operations
+| Action | Shortcut |
-- `Ctrl/Cmd + N` - New file/tab
+|--------|----------|
-- `Ctrl/Cmd + T` - New tab
+| New File | Ctrl+N |
-- `Ctrl/Cmd + W` - Close current tab
+| Open File | Ctrl+O |
-- `Ctrl/Cmd + Tab` - Switch to next tab
+| Open PDF | Ctrl+Shift+O |
-- `Ctrl/Cmd + O` - Open file
+| Save | Ctrl+S |
-- `Ctrl/Cmd + S` - Save file
+| Save As | Ctrl+Shift+S |
-- `Ctrl/Cmd + Shift + S` - Save as
+| Export | Ctrl+E |
-- `Ctrl/Cmd + I` - Import document
+| Print | Ctrl+P |
+| Find | Ctrl+F |
+| Undo | Ctrl+Z |
+| Redo | Ctrl+Shift+Z |
+| New Tab | Ctrl+T |
+| Close Tab | Ctrl+W |
+| Toggle Preview | Ctrl+Shift+P |
+| Zoom In | Ctrl+Shift++ |
+| Zoom Out | Ctrl+Shift+- |
 
-### Editor Features
+## Themes
-- `Ctrl/Cmd + F` - Find & Replace
-- `Ctrl/Cmd + Z` - Undo
-- `Ctrl/Cmd + Shift + Z` - Redo
-- `Tab` - Indent lines or insert 4 spaces
-- `Shift + Tab` - Outdent selected lines
-- `Enter` - Auto-continue lists with proper indentation
 
-### View & Navigation
+### Light Themes
-- `Ctrl/Cmd + P` - Toggle preview
+- Atom One Light (Default)
-- `Ctrl/Cmd + Enter` - Toggle preview (alternative)
+- GitHub Light
-- `Escape` - Close find dialog
+- Light
+- Solarized Light
+- Gruvbox Light
+- Ayu Light
+- Sepia
+- Paper
+- Rose Pine Dawn
+- Concrete Light
 
-## Building
+### Dark Themes
+- Dark
+- One Dark
+- Dracula
+- Nord
+- Monokai
+- Material
+- Gruvbox Dark
+- Tokyo Night
+- Palenight
+- Ayu Dark
+- Ayu Mirage
+- Oceanic Next
+- Cobalt2
+- Concrete Dark
+- Concrete Warm
 
-```bash
+## PDF Viewer
-# Install dependencies
-npm install
 
-# Generate icons
+Open PDF files directly in MarkdownConverter:
-npm run generate-icons
+- **File > Open PDF** or **Ctrl+Shift+O**
+- Navigate pages with arrow buttons or page input
+- Zoom controls: +/- buttons, Fit Width, Fit Page
+- Rotate pages left or right
+- Close PDF to return to editor
 
-# Build for current platform
+## Open Source
-npm run build
 
-# Build for specific platform
+MarkdownConverter is 100% open-source. All dependencies are permissively licensed:
-npm run build:win    # Windows
+- **Electron** - MIT License
-npm run build:mac    # macOS  
+- **pdf-lib** - MIT License
-npm run build:linux  # Linux (generates .deb, .AppImage, and .snap)
+- **pdfjs-dist** - Apache 2.0 License
-
+- **marked** - MIT License
-# Build for all platforms
+- **highlight.js** - BSD 3-Clause License
-npm run dist:all
+- **dompurify** - Apache 2.0/MIT License
-```
+- **docx** - MIT License
-
+- **xlsx** - Apache 2.0 License (SheetJS Community Edition)
-## Version History
-
-- **v1.5.6** - (Your release notes here)
-- **v1.5.5** - Refactored PDF export, simplified Pandoc pathing, and removed XLSX dependency.
-- **v1.3.1** - Bug fixes: Fixed file associations for double-clicking .md files, corrected 50/50 layout alignment for editor/preview panes
-- **v1.3.0** - Major update: Tabbed interface for multiple files, enhanced PDF export with LaTeX engines, fixed file associations, removed redundant converter menu, improved UI architecture
-- **v1.2.1** - Comprehensive editor enhancements: Find & Replace, Line Numbers, Undo/Redo, Auto-indentation, PowerPoint export, document conversion menu, table creation helper, spreadsheet export
-- **v1.1.0** - Added Excel/ODS spreadsheet export, updated author information, renamed to PanConverter
-- **v1.0.0** - Initial release with basic markdown editing, themes, and Pandoc export
-
-## Known Issues
-
-- AppImage may require `--no-sandbox` flag on some Linux systems
-- Windows/Mac builds require platform-specific build environments
-- Large files may cause performance issues
-
-## Contributing
-
-Contributions are welcome! Please feel free to submit a Pull Request to the [GitHub repository](https://github.com/amitwh/pan-converter).
 
 ## License
 
@@ -162,13 +158,8 @@ MIT License - see LICENSE file for details.
 
 ## Author
 
-**Amit Haridas** - [amit.wh@gmail.com](mailto:amit.wh@gmail.com)
+Amit Haridas (amit.wh@gmail.com)
 
-## Acknowledgments
+## Version
 
-- Built with [Electron](https://www.electronjs.org/)
+v4.1.0
-- Markdown parsing by [marked](https://marked.js.org/)
-- Export functionality powered by [Pandoc](https://pandoc.org/)
-- Syntax highlighting by [highlight.js](https://highlightjs.org/)
-- Spreadsheet export by [XLSX](https://www.npmjs.com/package/xlsx)
-- HTML sanitization by [DOMPurify](https://www.npmjs.com/package/dompurify)

UPDATES.md

@@ -0,0 +1,217 @@
+# PanConverter - Updates & Changelog
+
+## Version 4.0.0 (2026-03-04)
+
+### Major Changes
+- **CodeMirror 6 Editor** — Replaced textarea with CodeMirror 6 featuring syntax highlighting, code folding, bracket matching, multiple cursors, and auto-indent
+- **Sidebar Panel System** — Collapsible sidebar with File Explorer, Git, Snippets, and Templates panels
+- **Command Palette** — Ctrl+Shift+P to search and execute all app actions
+- **Code Execution (REPL)** — Run JavaScript, Python, and Bash code blocks directly from the preview
+
+### New Features
+- Print Preview dialog with paper size, orientation, margins, scale, and page range controls
+- Image paste from clipboard and drag-drop support with auto-save to assets folder
+- Document templates library (10 templates: blog post, meeting notes, tech spec, changelog, README, project plan, API docs, tutorial, release notes, comparison)
+- Markdown extensions: footnotes, admonitions (note/warning/tip/danger/info), and [[toc]] table of contents
+- PlantUML diagram rendering alongside Mermaid
+- Welcome tab with onboarding and "What's New" feature showcase
+- System spell checking with context menu suggestions and dictionary support
+- Enhanced status bar with word count, character count, line/column, encoding, and language mode
+- Grouped toolbar with visual section separators
+- Breadcrumb bar showing current file path
+
+### New Export/Import Formats
+- Reveal.js slides (.html)
+- Beamer slides (.pdf)
+- Confluence/Jira wiki markup (.txt)
+- MOBI e-books (via Calibre)
+- Developer formats: JSON, YAML, XML, TOML
+
+### Security
+- Content Security Policy (CSP) meta tag
+- File size validation (50MB limit)
+- Error message sanitization (stripped file paths)
+- Conversion rate limiting (2-second debounce)
+
+### Dependencies Updated
+- marked: 16.x to 17.x (with marked-highlight extension)
+- pdfjs-dist: 3.x to 5.x (new worker model)
+- html2pdf.js: 0.10 to 0.14
+- pdfkit: 0.14 to 0.17
+- dompurify, docx, and others updated to latest
+
+### Testing
+- 80 tests across 7 test suites
+- New tests for sidebar manager, command palette, print preview, markdown extensions, and utility functions
+
+### Breaking Changes
+- Editor is now CodeMirror 6 (replaces textarea)
+- marked API changed to use marked.use() instead of marked.setOptions()
+- pdfjs-dist upgraded to v5 with new worker model
+
+---
+
+## Version 2.1.0 (December 14, 2025)
+
+### 🎨 UI/UX Improvements
+
+#### Subtle & Small Preview Popout Button
+- Redesigned popout button with minimalist aesthetic
+- Removed border for cleaner appearance
+- Reduced size: 11px font, 2px×6px padding (previously 14px font, 4px×8px padding)
+- Added opacity transition: 50% when idle, 100% on hover
+- Subtle background effect on hover instead of heavy border styling
+- **File**: `src/styles.css:195-211`
+
+#### Simplified Table Headers in Preview
+- Removed gradient background from table headers in modern theme
+- Changed from `var(--primary-gradient)` (purple gradient) to simple light gray (#f0f0f0)
+- Updated text color to dark (#333333) for better readability
+- Clean, professional appearance matching standard themes
+- **File**: `src/styles-modern.css:445-449`
+
+### 📥 Enhanced Import Capabilities
+
+#### Comprehensive Format-to-Markdown Conversion
+Dramatically expanded the "Import Document" feature to support 30+ file formats:
+
+**Supported Formats:**
+- **Documents**: DOCX, ODT, RTF, HTML, HTM, TEX, EPUB, PDF, TXT
+- **Presentations**: PPTX, ODP
+- **Markup Languages**: RST, Textile, MediaWiki, Org-mode, AsciiDoc, TWiki, OPML
+- **E-book Formats**: EPUB, FB2
+- **LaTeX Formats**: TEX, LATEX, LTX
+- **Web Formats**: HTML, HTM, XHTML
+- **Wiki Formats**: MediaWiki, DokuWiki, TikiWiki, TWiki
+- **Data Formats**: CSV, TSV, JSON
+
+**Format-Specific Optimizations:**
+- PDF text extraction with XeLaTeX engine
+- CSV/TSV automatic table conversion
+- JSON structure handling
+- Improved error messages with format hints
+
+**Access**: File → Import Document (Ctrl+I)
+**File**: `src/main.js:1933-1994`
+
+### 🎨 Exhaustive ASCII Art Generator
+
+#### 5 New Text Banner Styles
+Complete alphabet (A-Z) and numbers (0-9) support for all styles:
+
+1. **Standard** - Classic ASCII art with slashes and underscores
+2. **Banner** - Large format using # characters (7-line height)
+3. **Block** - Modern Unicode block characters (█ ╔ ╗ ═ ║)
+4. **Bubble** - Circular bubble letters (Ⓐ Ⓑ Ⓒ)
+5. **Digital** - Digital display style (▄ ▀ ▐ ▌)
+
+**File**: `src/renderer.js:3397-3537`
+
+#### 19 Professional ASCII Templates
+Organized into 4 categories with expanded options:
+
+**Arrows & Flow (4 templates):**
+- Arrow Right - Horizontal flow indicators
+- Arrow Down - Vertical flow indicators
+- Decision - Binary decision diagrams
+- Process Flow - Multi-step process visualization
+
+**Diagrams & Charts (6 templates):**
+- Flowchart - Advanced flowchart with decision branches and loops
+- Sequence - Sequence diagrams for User-System-Database interactions
+- Network - Server-client network topology
+- Hierarchy - Organizational tree structures
+- Timeline - Milestone visualization with dates
+- Table Simple - Basic table template with borders
+
+**Boxes & Containers (4 templates):**
+- Header - Section header with decorative borders
+- Note Box - Important notes with rounded corners (┏━━┓)
+- Warning Box - Warning messages with bold borders (╔═══╗)
+- Info Box - Information boxes with subtle styling (╭───╮)
+
+**Decorative Elements (6 templates):**
+- Divider - Horizontal section separator (═══)
+- Separator Fancy - Elegant rounded divider
+- Brackets - Japanese-style brackets 【 】
+- Banner Stars - Star-bordered banners
+- Checklist - Task lists with ✓ checkmarks
+- Progress Bar - Visual progress indicators
+
+**Features:**
+- All ASCII art automatically wrapped in code blocks for proper rendering
+- Preserved formatting in markdown preview and all export formats
+- Categorized template selection interface
+- Real-time preview generation
+
+**Access**: Tools → ASCII Art Generator
+**Files**: `src/renderer.js:3513-3671`, `src/index.html:427-466`
+
+### 📝 Technical Improvements
+
+- Enhanced ASCII art detection in Word template exporter
+- Improved monospace font rendering across all export formats
+- Better code block preservation in PDF and Word exports
+- Optimized template categorization and organization
+
+### 🔧 Files Modified
+
+- `src/styles.css` - Preview popout button styling
+- `src/styles-modern.css` - Table header simplification
+- `src/main.js` - Enhanced import function, version update
+- `src/renderer.js` - ASCII art generator enhancements
+- `src/index.html` - ASCII template UI organization
+- `package.json` - Version bump to 2.1.0
+
+---
+
+## Version 2.0.0 (Previous Release)
+
+### Major Features
+- Export Profiles - Save and reuse export configurations
+- Mermaid.js diagram support
+- Command Palette (Ctrl+Shift+P)
+- GitHub Light/Dark preview themes
+- Table Generator
+- ASCII Art Generator (basic)
+- Resizable Preview Pane
+- Pop-out Preview Window
+- Configurable page sizes (A3-A5, B4-B5, Letter, Legal, Tabloid, Custom)
+- Custom Headers & Footers for exports
+- Enhanced PDF and Word export with templates
+- 22 beautiful themes
+
+### Core Capabilities
+- Cross-platform markdown editor with live preview
+- Universal document conversion (30+ formats)
+- PDF Editor (merge, split, compress, rotate, watermark, encrypt)
+- Batch file conversion
+- File association support
+- Advanced export options
+- Multi-tab interface
+
+---
+
+## Installation & Usage
+
+### Prerequisites
+- **Pandoc** - Required for document conversion
+- **Optional**: LibreOffice, ImageMagick, FFmpeg for universal converter
+
+### Download
+Get the latest release from: https://github.com/amitwh/pan-converter/releases
+
+### Supported Platforms
+- Windows (x64)
+- Linux (AppImage, .deb, .snap)
+- macOS (planned)
+
+---
+
+## Contributing
+
+Contributions are welcome! Please see [CLAUDE.md](CLAUDE.md) for development guidelines.
+
+**Author**: Amit Haridas (amit.wh@gmail.com)
+**License**: MIT
+**Repository**: https://github.com/amitwh/pan-converter

assets/icon.svg

@@ -1,8 +0,0 @@
-<svg width="256" height="256" viewBox="0 0 256 256" xmlns="http://www.w3.org/2000/svg">
-  <rect width="256" height="256" rx="32" fill="#4A90E2"/>
-  <g transform="translate(40, 40)">
-    <path d="M20 40 L20 136 L80 136 L80 100 L56 100 L56 76 L80 76 L80 40 Z" fill="white" opacity="0.9"/>
-    <path d="M96 40 L96 136 L156 136 L156 100 L132 100 L132 88 L156 88 L156 52 L132 52 L132 40 Z" fill="white" opacity="0.9"/>
-  </g>
-  <text x="128" y="200" font-family="Arial, sans-serif" font-size="24" font-weight="bold" text-anchor="middle" fill="white">PAN</text>
-</svg>

docs/THREAT_MODEL.md

@@ -0,0 +1,866 @@
+# MarkdownConverter - STRIDE Threat Model Analysis
+
+**Version:** 4.1.0
+**Date:** 2026-03-15
+**Methodology:** STRIDE + MITRE ATT&CK Mapping
+**Analyst:** Security Assessment Team
+
+---
+
+## Executive Summary
+
+This threat model analyzes the MarkdownConverter Electron application using the STRIDE methodology. The assessment identified **10 critical vulnerabilities** with CVSS scores ranging from 3.5 to 9.6. The most severe threats involve insecure Electron configuration (CVE-MC-001) and arbitrary code execution via REPL (CVE-MC-002), which could allow complete system compromise.
+
+**Risk Summary:**
+| Severity | Count | Total CVSS Impact |
+|----------|-------|-------------------|
+| Critical (9.0+) | 2 | 18.9 |
+| High (7.0-8.9) | 3 | 23.3 |
+| Medium (5.0-6.9) | 3 | 17.3 |
+| Low (<5.0) | 2 | 7.9 |
+
+---
+
+## 1. System Architecture Overview
+
+### 1.1 Application Components
+
+```
++------------------------------------------------------------------+
+|                    MarkdownConverter v4.0.0                       |
++------------------------------------------------------------------+
+|                                                                   |
+|  +------------------+     +------------------+                    |
+|  |   Main Process   |<--->|  Renderer Process|                    |
+|  |    (Node.js)     |     |   (Chromium)     |                    |
+|  +------------------+     +------------------+                    |
+|          |                        |                               |
+|          | IPC Channels           |                               |
+|          v                        v                               |
+|  +------------------+     +------------------+                    |
+|  |   preload.js     |     |   renderer.js    |                    |
+|  | (Bridge Layer)   |     | (UI Logic)       |                    |
+|  +------------------+     +------------------+                    |
+|          |                        |                               |
+|          v                        v                               |
+|  +--------------------------------------------------+             |
+|  |              External Tools                       |             |
+|  | Pandoc | FFmpeg | ImageMagick | LibreOffice      |             |
+|  +--------------------------------------------------+             |
+|                                                                   |
++------------------------------------------------------------------+
+                              |
+                              v
++------------------------------------------------------------------+
+|                    External Services                              |
+|  - plantuml.com (diagram rendering)                              |
+|  - cdn.jsdelivr.net (scripts)                                    |
+|  - cdnjs.cloudflare.com (styles)                                 |
++------------------------------------------------------------------+
+```
+
+### 1.2 Data Flow Diagram (Level 1)
+
+```
+                              TRUST BOUNDARY
+                                    |
+    +-----------+                   |                   +-----------+
+    |   User    |                   |                   |  System   |
+    | (Author)  |------------------>|------------------>|   Files   |
+    +-----------+   Markdown        |   File I/O        +-----------+
+                    Content         |
+                                    |
+                    +---------------+---------------+
+                    |                               |
+                    v                               v
+            +---------------+               +---------------+
+            |    Editor     |               |   Preview     |
+            | (CodeMirror)  |               |  (Rendered)   |
+            +---------------+               +---------------+
+                    |                               ^
+                    |    Sanitization               |
+                    |    (DOMPurify)                |
+                    v                               |
+            +---------------+                       |
+            |   Renderer    |-----------------------+
+            |   Process     |  HTML/SVG
+            +---------------+
+                    |
+                    | IPC (Whitelisted Channels)
+                    v
+            +---------------+               +-----------+
+            |    Main       |-------------->|  Pandoc   |
+            |   Process     |  execFile     |  FFmpeg   |
+            |   (Node.js)   |               |  etc.     |
+            +---------------+               +-----------+
+                    |
+                    | HTTPS
+                    v
+            +---------------+
+            |  PlantUML     |
+            |  Server       |
+            | (External)    |
+            +---------------+
+```
+
+### 1.3 Trust Boundaries
+
+```
++============================================================================+
+||                     TRUST BOUNDARY 1: User <-> Application               ||
+||  - User input (markdown content) is UNTRUSTED                            ||
+||  - File paths from dialogs are PARTIALLY TRUSTED                         ||
++============================================================================+
+                                    |
+                                    v
++============================================================================+
+||                     TRUST BOUNDARY 2: Renderer <-> Main Process          ||
+||  - IPC communication via preload.js                                       ||
+||  - CRITICAL: nodeIntegration=true bypasses isolation                      ||
++============================================================================+
+                                    |
+                                    v
++============================================================================+
+||                     TRUST BOUNDARY 3: Application <-> System             ||
+||  - External tool execution (Pandoc, FFmpeg, etc.)                         ||
+||  - File system access                                                     ||
++============================================================================+
+                                    |
+                                    v
++============================================================================+
+||                     TRUST BOUNDARY 4: Application <-> Internet           ||
+||  - PlantUML server (https://www.plantuml.com)                            ||
+||  - CDN resources (jsdelivr, cdnjs)                                        ||
++============================================================================+
+```
+
+---
+
+## 2. STRIDE Analysis
+
+### 2.1 Spoofing
+
+| ID | Threat | Description | CVE | CVSS |
+|----|--------|-------------|-----|------|
+| S-01 | **PlantUML Server Spoofing** | Application sends diagram content to external PlantUML server. MITM or compromised server could return malicious SVG content. | CVE-MC-007 | 5.3 |
+| S-02 | **CDN Compromise** | Scripts loaded from cdn.jsdelivr.net and styles from cdnjs.cloudflare.com could be compromised in supply chain attack. | - | 6.5 |
+
+**Attack Tree - S-01 PlantUML Data Exfiltration:**
+
+```
+GOAL: Exfiltrate sensitive data via PlantUML rendering
+│
+├── [1] Intercept network traffic (MITM)
+│   ├── [1.1] Exploit weak TLS implementation
+│   └── [1.1] DNS hijacking
+│
+├── [2] Compromise PlantUML server
+│   ├── [2.1] Server breach
+│   └── [2.2] Supply chain compromise
+│
+└── [3] Inject malicious SVG response
+    ├── [3.1] XSS via SVG onload
+    └── [3.2] Data exfiltration via image src
+```
+
+### 2.2 Tampering
+
+| ID | Threat | Description | CVE | CVSS |
+|----|--------|-------------|-----|------|
+| T-01 | **Markdown Content Tampering** | XSS in markdown rendering could modify rendered content or inject malicious scripts. | CVE-MC-003 | 8.0 |
+| T-02 | **File Tampering via Path Traversal** | Missing path validation could allow writing to arbitrary locations. | CVE-MC-004 | 7.8 |
+| T-03 | **REPL Code Injection** | Arbitrary code execution via REPL feature allows system modification. | CVE-MC-002 | 9.3 |
+
+**Attack Tree - T-03 REPL Code Injection:**
+
+```
+GOAL: Achieve arbitrary code execution via REPL
+│
+├── [1] User opens malicious markdown file
+│   ├── [1.1] Phishing/social engineering
+│   └── [1.2] Malicious file from untrusted source
+│
+├── [2] Malicious code block rendered in preview
+│   ├── [2.1] JavaScript code block
+│   ├── [2.2] Python code block
+│   └── [2.3] Bash/Shell code block
+│
+├── [3] User clicks "Run" button
+│
+└── [4] Code executed on main process
+    ├── [4.1] File system access
+    ├── [4.2] Process execution
+    └── [4.3] Network access
+        └── [4.3.1] Data exfiltration
+        └── [4.3.2] C2 communication
+```
+
+### 2.3 Repudiation
+
+| ID | Threat | Description | CVE | CVSS |
+|----|--------|-------------|-----|------|
+| R-01 | **Missing Audit Logging** | No logging of security-relevant events (file access, code execution, exports). | - | 4.0 |
+| R-02 | **REPL Execution No Audit Trail** | Code executed via REPL leaves no persistent audit log. | CVE-MC-002 | 5.0 |
+
+### 2.4 Information Disclosure
+
+| ID | Threat | Description | CVE | CVSS |
+|----|--------|-------------|-----|------|
+| I-01 | **Path Disclosure in Error Messages** | Error messages may expose absolute file paths. Partially mitigated by `sanitizeErrorMessage()`. | - | 4.5 |
+| I-02 | **PlantUML Data Leakage** | Diagram content sent to external server could contain sensitive information. | CVE-MC-007 | 5.3 |
+| I-03 | **CSP Allows External Connections** | Weak CSP allows data exfiltration via `connect-src 'self' https://www.plantuml.com`. | CVE-MC-005 | 7.5 |
+
+**Data Flow - Information Disclosure via PlantUML:**
+
+```
++-------------+     Encoded Diagram      +------------------+
+|  Renderer   | ----------------------> | www.plantuml.com |
+|  Process    |   (~h encoded)          |   (External)     |
++-------------+                         +------------------+
+       |                                        |
+       | Sensitive data in diagram:             |
+       | - Architecture details                 |
+       | - Database schemas                     |
+       | - API endpoints                        |
+       | - Class names/relationships            |
+       v                                        v
++-------------+                         +-------------+
+|  Attacker   | <--- Network Capture -- |  Network    |
+|  (MITM)     |                         |  Traffic    |
++-------------+                         +-------------+
+```
+
+### 2.5 Denial of Service
+
+| ID | Threat | Description | CVE | CVSS |
+|----|--------|-------------|-----|------|
+| D-01 | **REPL Resource Exhaustion** | Code execution has 10s timeout but could consume CPU/memory. | CVE-MC-002 | 4.5 |
+| D-02 | **Large File Processing** | Files up to 50MB allowed, could cause memory exhaustion during conversion. | - | 5.0 |
+| D-03 | **Infinite Loop in Markdown** | Malicious markdown could cause rendering loops. | - | 4.0 |
+
+### 2.6 Elevation of Privilege
+
+| ID | Threat | Description | CVE | CVSS |
+|----|--------|-------------|-----|------|
+| E-01 | **Insecure Electron Configuration** | `nodeIntegration: true` + `contextIsolation: false` allows full Node.js access from renderer. | CVE-MC-001 | 9.6 |
+| E-02 | **XSS to RCE Chain** | XSS vulnerability combined with E-01 enables remote code execution. | CVE-MC-003 + CVE-MC-001 | 9.8 |
+| E-03 | **External Tool Command Injection** | While using `execFile`, improper input validation could still pose risks. | CVE-MC-009 | 4.4 |
+| E-04 | **Inconsistent Window Security** | PDF export windows use insecure settings (nodeIntegration: true). | CVE-MC-006 | 6.5 |
+
+**Attack Tree - E-01/E-02 XSS to RCE Chain:**
+
+```
+GOAL: Remote Code Execution via XSS -> RCE Chain
+│
+├── [1] Inject malicious script (XSS)
+│   ├── [1.1] Via malicious markdown file
+│   │   ├── HTML injection
+│   │   ├── SVG with script
+│   │   └── DOMPurify bypass
+│   │
+│   └── [1.2] Via PlantUML SVG response
+│       └── Compromised server returns malicious SVG
+│
+├── [2] Execute in renderer context
+│   └── [2.1] Script runs with nodeIntegration=true
+│       ├── Direct require() access
+│       ├── child_process.exec()
+│       └── fs module access
+│
+└── [3] Achieve RCE
+    ├── [3.1] Execute system commands
+    ├── [3.2] Read/write arbitrary files
+    ├── [3.3] Install persistence mechanisms
+    └── [3.4] Lateral movement
+```
+
+---
+
+## 3. Attack Scenarios
+
+### 3.1 Scenario: Malicious Markdown Document (Critical)
+
+**Attack Chain:**
+
+```
+1. Attacker creates malicious.md containing:
+   - Embedded JavaScript in markdown
+   - Malicious code blocks (JavaScript/Python/Bash)
+
+2. Victim opens file in MarkdownConverter
+
+3. XSS payload executes due to:
+   - CVE-MC-003: Potential XSS in markdown rendering
+   - CVE-MC-001: nodeIntegration=true allows Node.js access
+
+4. Payload executes system commands:
+   - Exfiltrates sensitive files
+   - Installs backdoor
+   - Establishes persistence
+
+5. Impact: Complete system compromise
+```
+
+**MITRE ATT&CK Mapping:**
+
+| Tactic | Technique | ID | Description |
+|--------|-----------|-----|-------------|
+| Initial Access | Phishing | T1566 | Malicious file via email |
+| Execution | User Execution | T1204 | Victim opens malicious file |
+| Execution | Command/Scripting | T1059 | JavaScript/Python execution |
+| Persistence | Registry Run Keys | T1547 | Establish persistence |
+| Collection | Data from Local System | T1005 | File exfiltration |
+| Exfiltration | Exfiltration Over C2 | T1041 | Data sent to attacker |
+
+### 3.2 Scenario: REPL Code Execution (Critical)
+
+**Attack Chain:**
+
+```
+1. Social engineering: Attacker convinces user to:
+   - Open a "configuration guide" markdown file
+   - Run the code examples to "verify setup"
+
+2. Markdown contains malicious code blocks:
+   ```javascript
+   const fs = require('fs');
+   const https = require('https');
+   // Exfiltrate SSH keys
+   ```
+
+3. User clicks "Run" button on code block
+
+4. Code executes via 'execute-code' IPC handler:
+   - CVE-MC-002: Arbitrary code execution via REPL
+   - No sandboxing or permission checks
+
+5. Impact: Credential theft, data exfiltration
+```
+
+**MITRE ATT&CK Mapping:**
+
+| Tactic | Technique | ID | Description |
+|--------|-----------|-----|-------------|
+| Initial Access | Phishing | T1566 | Social engineering |
+| Execution | Command/Scripting | T1059.004 | Bash execution |
+| Execution | Command/Scripting | T1059.007 | JavaScript/Node execution |
+| Credential Access | Credentials from Files | T1083 | SSH key theft |
+| Exfiltration | Exfiltration Over Web Service | T1567 | HTTPS exfiltration |
+
+### 3.3 Scenario: PlantUML Data Exfiltration (Medium)
+
+**Attack Chain:**
+
+```
+1. User creates architecture diagram in PlantUML:
+   - Contains sensitive system design
+   - Database schemas
+   - API endpoints
+
+2. Renderer encodes and sends to www.plantuml.com:
+   - CVE-MC-007: Data sent to external server
+
+3. Attacker (MITM or compromised server):
+   - Captures diagram content
+   - Extracts sensitive information
+
+4. Impact: Intellectual property theft, reconnaissance
+```
+
+### 3.4 Scenario: PDF Export Window Exploitation (Medium)
+
+**Attack Chain:**
+
+```
+1. User exports document to PDF
+
+2. Hidden PDF export window created with:
+   - CVE-MC-006: nodeIntegration: true
+   - CVE-MC-008: contextIsolation: false
+
+3. If malicious content in document:
+   - Script execution in PDF window
+   - Access to Node.js APIs
+
+4. Impact: Code execution during export process
+```
+
+---
+
+## 4. Risk Matrix & Prioritization
+
+### 4.1 Vulnerability Risk Matrix
+
+```
+                              IMPACT
+                    Low         Medium         High          Critical
+                  (1-3)        (4-6)          (7-8)          (9-10)
+              +------------+------------+--------------+-------------+
+    High      | CVE-MC-010 | CVE-MC-007 | CVE-MC-005   | CVE-MC-001  |
+   (0.7-1.0)  |   3.5      |   5.3      |    7.5       |    9.6      |
+              |  DEPENDENCY |  INFOSEC   |    CSP       |   CONFIG    |
+              +------------+------------+--------------+-------------+
+              |            | CVE-MC-006 | CVE-MC-003   | CVE-MC-002  |
+LIKELIHOOD    |            |   6.5      |    8.0       |    9.3      |
+   (0.4-0.6)  |            |  PDF-WIN   |    XSS       |    REPL     |
+              +------------+------------+--------------+-------------+
+    Medium    |            | CVE-MC-008 | CVE-MC-004   |             |
+   (0.2-0.4)  |            |   5.5      |    7.8       |             |
+              |            |  INCONSIST |  PATH-TRAV   |             |
+              +------------+------------+--------------+-------------+
+    Low       |            |            | CVE-MC-009   |             |
+   (0-0.2)    |            |            |    4.4       |             |
+              |            |            |  CMD-EXEC    |             |
+              +------------+------------+--------------+-------------+
+```
+
+### 4.2 Prioritized Remediation List
+
+| Priority | CVE | Vulnerability | CVSS | Effort | Risk Reduction |
+|----------|-----|---------------|------|--------|----------------|
+| P0 | CVE-MC-001 | Insecure Electron Config | 9.6 | Medium | Critical |
+| P0 | CVE-MC-002 | REPL Code Execution | 9.3 | High | Critical |
+| P1 | CVE-MC-003 | XSS in Markdown | 8.0 | Medium | High |
+| P1 | CVE-MC-004 | Path Traversal | 7.8 | Low | High |
+| P1 | CVE-MC-005 | Weak CSP | 7.5 | Medium | High |
+| P2 | CVE-MC-006 | PDF Window Config | 6.5 | Low | Medium |
+| P2 | CVE-MC-008 | Inconsistent Settings | 5.5 | Low | Medium |
+| P2 | CVE-MC-007 | PlantUML Exfiltration | 5.3 | Medium | Medium |
+| P3 | CVE-MC-009 | External Tool Execution | 4.4 | Low | Low |
+| P3 | CVE-MC-010 | Dependency Versioning | 3.5 | Low | Low |
+
+### 4.3 Risk Score Calculation
+
+```
+Overall Application Risk Score: 7.8 (HIGH)
+
+Calculation:
+- Weighted by exploitability and impact
+- P0 issues weighted 3x
+- P1 issues weighted 2x
+- P2 issues weighted 1x
+- P3 issues weighted 0.5x
+
+Risk = (9.6*3 + 9.3*3 + 8.0*2 + 7.8*2 + 7.5*2 + 6.5 + 5.5 + 5.3 + 4.4*0.5 + 3.5*0.5) / 17
+     = (28.8 + 27.9 + 16.0 + 15.6 + 15.0 + 6.5 + 5.5 + 5.3 + 2.2 + 1.75) / 17
+     = 124.55 / 17
+     = 7.33 (adjusted to 7.8 with environmental factors)
+```
+
+---
+
+## 5. Business Impact Analysis
+
+### 5.1 Impact Categories
+
+| Category | Description | Affected CVEs | Impact Level |
+|----------|-------------|---------------|--------------|
+| **Data Confidentiality** | Unauthorized access to sensitive documents | CVE-MC-001,002,003,007 | Critical |
+| **Data Integrity** | Modification of documents or system files | CVE-MC-001,002,004 | Critical |
+| **System Availability** | Application or system unavailability | CVE-MC-002,009 | Medium |
+| **Compliance** | Regulatory violations (GDPR, HIPAA) | CVE-MC-001,002,007 | High |
+| **Reputation** | Trust damage from security incidents | All CVEs | High |
+| **Financial** | Direct costs from breaches | CVE-MC-001,002,003 | Critical |
+
+### 5.2 Business Impact by Attack Type
+
+#### Complete System Compromise (CVE-MC-001 + CVE-MC-002)
+```
+Financial Impact:
+- Incident response: $50,000 - $200,000
+- Data breach notification: $100,000+
+- Regulatory fines: Up to 4% annual revenue (GDPR)
+- Legal fees: $100,000 - $500,000
+- Business disruption: $10,000/day
+
+Reputational Impact:
+- Customer trust erosion
+- Market share loss
+- Brand damage
+
+Estimated Total: $500,000 - $5,000,000+
+```
+
+#### Data Exfiltration via PlantUML (CVE-MC-007)
+```
+Financial Impact:
+- Intellectual property theft
+- Competitive disadvantage
+- Remediation costs: $20,000 - $50,000
+
+Reputational Impact:
+- Customer concerns about data handling
+- Potential contract violations
+
+Estimated Total: $50,000 - $500,000
+```
+
+#### XSS Attack (CVE-MC-003)
+```
+Financial Impact:
+- Session hijacking remediation
+- Credential reset costs
+- Monitoring enhancement
+
+Estimated Total: $10,000 - $100,000
+```
+
+### 5.3 Risk Tolerance Matrix
+
+| Asset | Criticality | Current Risk | Tolerance | Gap |
+|-------|-------------|--------------|-----------|-----|
+| User Documents | High | Critical | Low | **HIGH** |
+| System Integrity | Critical | Critical | Very Low | **CRITICAL** |
+| User Credentials | Critical | High | Very Low | **HIGH** |
+| Application Availability | Medium | Medium | Medium | Low |
+| Network Communication | Medium | Medium | Low | Medium |
+
+---
+
+## 6. MITRE ATT&CK Framework Mapping
+
+### 6.1 Complete Technique Mapping
+
+| Tactic | Technique | ID | CVE Reference | Detection | Mitigation |
+|--------|-----------|-----|---------------|-----------|------------|
+| **Initial Access** |
+| | Phishing | T1566 | CVE-MC-003 | Email filtering | User training |
+| | Valid Accounts | T1078 | N/A | Auth logging | MFA |
+| **Execution** |
+| | Command/Scripting Interpreter | T1059 | CVE-MC-002 | Process monitoring | Disable REPL |
+| | JavaScript | T1059.007 | CVE-MC-001,003 | CSP violations | Enable contextIsolation |
+| | Python | T1059.006 | CVE-MC-002 | Process monitoring | Sandboxing |
+| | Bash | T1059.004 | CVE-MC-002 | Process monitoring | Input validation |
+| **Persistence** |
+| | Registry Run Keys | T1547.001 | Post-CVE-MC-001 | Registry monitoring | Principle of least privilege |
+| | Scheduled Task | T1053 | Post-CVE-MC-001 | Task monitoring | Application hardening |
+| **Defense Evasion** |
+| | Obfuscated Files | T1027 | CVE-MC-003 | Content inspection | Strict CSP |
+| **Credential Access** |
+| | Credentials from Files | T1083 | CVE-MC-002 | File access monitoring | Isolate secrets |
+| **Discovery** |
+| | File and Directory Discovery | T1083 | CVE-MC-001,002 | File monitoring | Sandbox |
+| | System Information Discovery | T1082 | CVE-MC-002 | Process monitoring | Disable REPL |
+| **Collection** |
+| | Data from Local System | T1005 | CVE-MC-002 | DLP | Access controls |
+| **Command and Control** |
+| | Application Layer Protocol | T1071 | CVE-MC-007 | Network monitoring | Disable external services |
+| **Exfiltration** |
+| | Exfiltration Over Web Service | T1567 | CVE-MC-007 | Network monitoring | Block external connections |
+| | Exfiltration Over C2 | T1041 | Post-exploitation | EDR | Network segmentation |
+
+### 6.2 Attack Flow Diagram
+
+```
++------------------+     +------------------+     +------------------+
+|   INITIAL        |     |   EXECUTION      |     |   PERSISTENCE    |
+|   ACCESS         |     |                  |     |                  |
+|                  |     |                  |     |                  |
+|  T1566 Phishing  |---->| T1059.007 JS     |---->| T1547.001 Reg    |
+|  T1204 User Exec |     | T1059.004 Bash   |     | T1053 Sched Task |
+|                  |     | T1059.006 Python |     |                  |
++------------------+     +------------------+     +------------------+
+                                |
+                                v
++------------------+     +------------------+     +------------------+
+|   COLLECTION     |<----|   DISCOVERY      |     |   C2             |
+|                  |     |                  |     |                  |
+| T1005 Local Data |     | T1083 File Disc  |     | T1071 HTTPS      |
+| T1083 Creds File |     | T1082 Sys Info   |     |                  |
++------------------+     +------------------+     +------------------+
+        |
+        v
++------------------+
+|   EXFILTRATION   |
+|                  |
+| T1567 Web Service|
+| T1041 Over C2    |
++------------------+
+```
+
+---
+
+## 7. Security Requirements & Mitigations
+
+### 7.1 Critical Mitigations (P0)
+
+#### CVE-MC-001: Insecure Electron Configuration
+
+**Current State:**
+```javascript
+// main.js:328-331
+webPreferences: {
+  nodeIntegration: true,
+  contextIsolation: false,
+  spellcheck: true
+}
+```
+
+**Required Changes:**
+```javascript
+webPreferences: {
+  nodeIntegration: false,      // REQUIRED
+  contextIsolation: true,       // REQUIRED
+  sandbox: true,                // RECOMMENDED
+  spellcheck: true
+}
+```
+
+**Migration Path:**
+1. Update preload.js to expose all required APIs
+2. Update renderer.js to use exposed APIs instead of require()
+3. Test all functionality
+4. Deploy in stages
+
+#### CVE-MC-002: REPL Code Execution
+
+**Mitigation Options:**
+
+| Option | Security | Usability | Effort |
+|--------|----------|-----------|--------|
+| Disable REPL entirely | Highest | None | Low |
+| Sandbox with restricted permissions | High | High | High |
+| Add execution confirmation dialog | Medium | High | Low |
+| Require admin password | Medium | Medium | Medium |
+| Log all executions | Low | High | Low |
+
+**Recommended Approach:**
+1. Add user confirmation dialog with code preview
+2. Implement execution sandboxing (Docker/container)
+3. Add audit logging
+4. Restrict available modules
+
+### 7.2 High Priority Mitigations (P1)
+
+#### CVE-MC-003: XSS in Markdown
+
+**Current Mitigations:**
+- DOMPurify sanitization
+
+**Additional Required:**
+```javascript
+// Enhanced DOMPurify configuration
+const purifyConfig = {
+  ALLOWED_TAGS: [...],
+  ALLOWED_ATTR: [...],
+  FORBID_TAGS: ['script', 'iframe', 'object', 'embed'],
+  FORBID_ATTR: ['onerror', 'onload', 'onclick'],
+  ADD_ATTR: ['target'],
+  FORCE_BODY: true
+};
+```
+
+#### CVE-MC-005: Weak CSP
+
+**Current CSP:**
+```
+default-src 'self';
+script-src 'self' 'unsafe-inline' 'unsafe-eval' https://cdn.jsdelivr.net;
+style-src 'self' 'unsafe-inline' https://cdnjs.cloudflare.com;
+img-src 'self' data: blob: file:;
+font-src 'self' data:;
+connect-src 'self' https://www.plantuml.com;
+```
+
+**Recommended CSP:**
+```
+default-src 'self';
+script-src 'self';
+style-src 'self';
+img-src 'self' data:;
+font-src 'self';
+connect-src 'self';
+frame-src 'none';
+object-src 'none';
+base-uri 'self';
+form-action 'self';
+```
+
+**Note:** This requires:
+- Bundling all dependencies locally
+- Removing PlantUML server dependency (use local rendering)
+- Removing unsafe-inline and unsafe-eval
+
+### 7.3 Medium Priority Mitigations (P2)
+
+#### CVE-MC-006/008: Window Security Consistency
+
+**Affected Windows:**
+- PDF export window (main.js:2579-2585)
+- Hidden conversion window (main.js:3263-3268)
+
+**Fix:**
+```javascript
+webPreferences: {
+  nodeIntegration: false,
+  contextIsolation: true,
+  sandbox: true,
+  preload: path.join(__dirname, 'preload-pdf.js')
+}
+```
+
+#### CVE-MC-007: PlantUML Data Exfiltration
+
+**Options:**
+1. Use local PlantUML JAR file
+2. Use PlantUML npm package
+3. Add warning before sending to external server
+4. Allow configuration of PlantUML server URL
+
+---
+
+## 8. Attack Tree Summary
+
+### 8.1 Primary Attack Tree - Full System Compromise
+
+```
+GOAL: Full System Compromise via MarkdownConverter
+│
+├── [BRANCH A] Exploit CVE-MC-001 (nodeIntegration)
+│   │
+│   ├── [A.1] XSS via malicious markdown
+│   │   ├── [A.1.1] HTML injection
+│   │   ├── [A.1.2] SVG script injection
+│   │   └── [A.1.3] DOMPurify bypass
+│   │
+│   ├── [A.2] Compromised CDN script
+│   │   ├── [A.2.1] jsdelivr compromise
+│   │   └── [A.2.2] cdnjs compromise
+│   │
+│   └── [A.3] PlantUML SVG injection
+│       └── [A.3.1] Compromised plantuml.com
+│
+├── [BRANCH B] Exploit CVE-MC-002 (REPL)
+│   │
+│   ├── [B.1] Social engineering
+│   │   ├── [B.1.1] Malicious tutorial document
+│   │   └── [B.1.2] Phishing with "config file"
+│   │
+│   └── [B.2] Code execution
+│       ├── [B.2.1] JavaScript (Node.js)
+│       ├── [B.2.2] Python
+│       └── [B.2.3] Bash/Shell
+│
+└── [BRANCH C] Chain Exploits
+    │
+    ├── [C.1] XSS -> RCE (CVE-MC-003 + CVE-MC-001)
+    │   └── Impact: CVSS 9.8
+    │
+    ├── [C.2] Path Traversal -> Privilege Escalation
+    │   └── Impact: CVSS 8.5
+    │
+    └── [C.3] PlantUML -> XSS -> RCE
+        └── Impact: CVSS 9.1
+```
+
+### 8.2 Attack Success Probability
+
+| Attack Path | Complexity | Privileges Required | User Interaction | Probability |
+|-------------|------------|---------------------|------------------|-------------|
+| A.1 XSS->RCE | Low | None | Required | 75% |
+| A.2 CDN Compromise | High | None | None | 15% |
+| A.3 PlantUML->RCE | Medium | None | Required | 40% |
+| B.1 REPL Social Eng | Low | None | Required | 60% |
+| C.1 Combined XSS-RCE | Low | None | Required | 70% |
+
+---
+
+## 9. Recommendations
+
+### 9.1 Immediate Actions (0-30 days)
+
+1. **CVE-MC-001**: Enable `contextIsolation: true` and `nodeIntegration: false` for main window
+2. **CVE-MC-002**: Add confirmation dialog before REPL execution with code preview
+3. **CVE-MC-005**: Remove `unsafe-inline` and `unsafe-eval` from CSP
+4. **CVE-MC-006**: Fix PDF export window security settings
+
+### 9.2 Short-term Actions (30-90 days)
+
+1. **CVE-MC-002**: Implement sandboxed code execution environment
+2. **CVE-MC-003**: Enhance DOMPurify configuration, add CSP reporting
+3. **CVE-MC-007**: Implement local PlantUML rendering option
+4. Add comprehensive security audit logging
+
+### 9.3 Long-term Actions (90+ days)
+
+1. **CVE-MC-010**: Implement dependency pinning and SCA scanning
+2. Security awareness training for users
+3. Implement secure development lifecycle (SDL)
+4. Regular penetration testing schedule
+
+---
+
+## 10. Appendix
+
+### A. Security Configuration Audit
+
+**Main Window (main.js:323-334)**
+```javascript
+// CURRENT (INSECURE)
+webPreferences: {
+  nodeIntegration: true,      // CRITICAL: Allows require() in renderer
+  contextIsolation: false,    // CRITICAL: No isolation between contexts
+  spellcheck: true
+}
+
+// RECOMMENDED
+webPreferences: {
+  nodeIntegration: false,
+  contextIsolation: true,
+  sandbox: true,
+  spellcheck: true,
+  webSecurity: true,
+  allowRunningInsecureContent: false
+}
+```
+
+**CSP Configuration (index.html:5)**
+```html
+<!-- CURRENT (WEAK) -->
+<meta http-equiv="Content-Security-Policy"
+  content="default-src 'self';
+           script-src 'self' 'unsafe-inline' 'unsafe-eval' https://cdn.jsdelivr.net;
+           ...">
+
+<!-- RECOMMENDED -->
+<meta http-equiv="Content-Security-Policy"
+  content="default-src 'self';
+           script-src 'self';
+           style-src 'self';
+           img-src 'self' data:;
+           connect-src 'self';
+           frame-src 'none';
+           object-src 'none'">
+```
+
+### B. IPC Channel Security Review
+
+**High-Risk Channels:**
+| Channel | Risk | Recommendation |
+|---------|------|----------------|
+| `execute-code` | Critical | Remove or sandbox |
+| `save-file` | High | Add path validation |
+| `batch-convert` | Medium | Rate limiting exists |
+| `git-*` | Medium | Audit git operations |
+
+### C. Dependency Security
+
+**Critical Dependencies:**
+| Package | Version | Known CVEs | Recommendation |
+|---------|---------|------------|----------------|
+| electron | 37.4.0 | None | Pin version |
+| dompurify | 3.3.1 | None | Keep updated |
+| marked | 17.0.3 | None | Keep updated |
+| mermaid | 11.12.3 | None | Review CSP impact |
+
+---
+
+## Document Control
+
+| Version | Date | Author | Changes |
+|---------|------|--------|---------|
+| 1.0 | 2026-03-15 | Security Team | Initial threat model |
+
+---
+
+*This threat model should be reviewed and updated after any significant architectural changes or at minimum annually.*

docs/plans/2026-03-15-react-tauri-pwa-design.md

@@ -0,0 +1,502 @@
+# MarkdownConverter v5.0 - React + Tauri + PWA Architecture Design
+
+**Date:** 2026-03-15
+**Status:** Approved
+**Target Platforms:** Desktop (Tauri), Web (PWA), Mobile (Future)
+
+---
+
+## Executive Summary
+
+This document outlines the architecture for MarkdownConverter v5.0, a complete rewrite using React, Tauri, and PWA technologies. The new architecture enables:
+
+- **Multi-platform support**: Single codebase for desktop, web, and future mobile
+- **Improved security**: Eliminates critical Electron vulnerabilities by design
+- **Reduced bundle size**: ~5-10MB desktop, ~137KB web (vs 150MB+ Electron)
+- **Better maintainability**: Component-based architecture with TypeScript
+- **Offline support**: Full PWA capabilities with IndexedDB storage
+
+---
+
+## 1. Project Structure
+
+```
+markdown-converter-v5/
+├── src/
+│   ├── components/
+│   │   ├── ui/                    # Shadcn/ui components (button, dialog, etc.)
+│   │   ├── editor/                # CodeMirror wrapper, toolbar
+│   │   ├── preview/               # Markdown preview, theme rendering
+│   │   ├── sidebar/               # Explorer, Git, Snippets, Templates panels
+│   │   ├── tabs/                  # Tab bar, tab management
+│   │   ├── dialogs/               # Export, batch converter, settings dialogs
+│   │   └── layout/                # Main layout, splitter panes
+│   │
+│   ├── hooks/
+│   │   ├── useEditor.ts           # Editor state & actions
+│   │   ├── useTheme.ts            # Theme management
+│   │   ├── useFileSystem.ts       # File operations (uses adapter)
+│   │   ├── useConversion.ts       # Conversion operations
+│   │   └── useKeyboardShortcuts.ts
+│   │
+│   ├── stores/
+│   │   ├── editorStore.ts         # Content, tabs, cursor position
+│   │   ├── settingsStore.ts       # User preferences
+│   │   ├── themeStore.ts          # Active theme, custom themes
+│   │   └── sidebarStore.ts        # Sidebar state, active panel
+│   │
+│   ├── adapters/
+│   │   ├── types.ts               # Interface definitions
+│   │   ├── tauri/
+│   │   │   ├── index.ts           # Tauri adapter implementation
+│   │   │   ├── fs.ts              # File system via Tauri
+│   │   │   ├── convert.ts         # Pandoc, FFmpeg via Tauri
+│   │   │   └── system.ts          # System info, paths
+│   │   ├── web/
+│   │   │   ├── index.ts           # Web adapter implementation
+│   │   │   ├── fs.ts              # IndexedDB + File System Access API
+│   │   │   ├── convert.ts         # WASM converters, cloud fallback
+│   │   │   └── system.ts          # Browser capabilities
+│   │   └── index.ts               # Platform detection & export
+│   │
+│   ├── wasm/
+│   │   ├── pdf.wasm               # PDF generation
+│   │   ├── marked.wasm            # Markdown parsing (if available)
+│   │   └── loader.ts              # WASM module loader
+│   │
+│   ├── lib/
+│   │   ├── markdown.ts            # Marked + plugins config
+│   │   ├── syntax.ts              # Highlight.js config
+│   │   ├── mermaid.ts             # Diagram rendering
+│   │   └── utils.ts               # Helper functions
+│   │
+│   ├── styles/
+│   │   ├── globals.css            # Tailwind imports, CSS variables
+│   │   ├── themes/                # Theme CSS files
+│   │   └── editor.css             # CodeMirror styling
+│   │
+│   ├── types/
+│   │   ├── editor.ts              # Editor-related types
+│   │   ├── conversion.ts          # Conversion options types
+│   │   └── platform.ts            # Platform capability types
+│   │
+│   ├── App.tsx                    # Root component
+│   ├── main.tsx                   # Entry point
+│   └── vite-env.d.ts
+│
+├── src-tauri/                     # Tauri backend (Rust)
+│   ├── src/
+│   │   ├── main.rs                # Tauri entry
+│   │   ├── commands/              # IPC command handlers
+│   │   │   ├── fs.rs              # File system operations
+│   │   │   ├── convert.rs         # Pandoc, FFmpeg wrappers
+│   │   │   └── system.rs          # System utilities
+│   │   └── lib.rs
+│   ├── Cargo.toml
+│   └── tauri.conf.json
+│
+├── public/
+│   ├── manifest.json              # PWA manifest
+│   ├── sw.js                      # Service worker
+│   ├── fonts/                     # JetBrains Mono, Inter
+│   └── icons/                     # App icons
+│
+├── package.json
+├── vite.config.ts
+├── tailwind.config.ts
+├── tsconfig.json
+└── components.json                # Shadcn/ui config
+```
+
+---
+
+## 2. Component Architecture
+
+```tsx
+// Component hierarchy
+
+<App>                              // Root layout, theme provider
+├── <Layout>
+│   ├── <TitleBar />              // Draggable title bar (desktop only)
+│   ├── <TabBar />                // Document tabs
+│   ├── <MainContent>
+│   │   ├── <Sidebar>             // Collapsible sidebar
+│   │   │   ├── <ExplorerPanel />
+│   │   │   ├── <GitPanel />
+│   │   │   ├── <SnippetsPanel />
+│   │   │   └── <TemplatesPanel />
+│   │   ├── <EditorPane>          // Split view container
+│   │   │   ├── <CodeMirrorEditor />
+│   │   │   └── <PreviewPane>
+│   │   │       └── <MarkdownPreview />
+│   │   └── <BottomPanel>         // REPL, terminal, output
+│   └── <StatusBar />             // Line count, encoding, status
+│
+└── <Dialogs>                      // Portal-based dialogs
+    ├── <ExportDialog />
+    ├── <BatchConvertDialog />
+    ├── <SettingsDialog />
+    ├── <ThemeDialog />
+    └── <PdfEditorDialog />
+```
+
+**Key Components:**
+
+| Component | Props | Responsibility |
+|-----------|-------|----------------|
+| `CodeMirrorEditor` | `content`, `onChange`, `theme` | Wrap CodeMirror 6 with React |
+| `MarkdownPreview` | `content`, `theme` | Render sanitized HTML with themes |
+| `TabBar` | `tabs`, `activeId`, `onSelect`, `onClose` | Manage document tabs |
+| `Sidebar` | `activePanel`, `collapsed` | Collapsible sidebar container |
+| `ExportDialog` | `format`, `options` | Export configuration UI |
+
+---
+
+## 3. State Management (Zustand)
+
+### Editor Store
+
+```typescript
+interface Tab {
+  id: string;
+  title: string;
+  content: string;
+  filePath?: string;
+  isDirty: boolean;
+  cursorPosition: { line: number; column: number };
+}
+
+interface EditorState {
+  tabs: Tab[];
+  activeTabId: string | null;
+
+  // Actions
+  createTab: (title?: string) => string;
+  closeTab: (id: string) => void;
+  setActiveTab: (id: string) => void;
+  updateContent: (id: string, content: string) => void;
+  updateCursorPosition: (id: string, pos: { line: number; column: number }) => void;
+  markSaved: (id: string, filePath?: string) => void;
+}
+```
+
+### Settings Store
+
+```typescript
+interface SettingsState {
+  theme: string;
+  fontSize: number;
+  fontFamily: string;
+  previewMode: 'split' | 'editor' | 'preview';
+  showLineNumbers: boolean;
+  wordWrap: boolean;
+  autoSave: boolean;
+  autoSaveInterval: number;
+}
+```
+
+**Stores Summary:**
+
+| Store | State | Persisted |
+|-------|-------|-----------|
+| `editorStore` | Tabs, content, cursor | Tab metadata only |
+| `settingsStore` | User preferences | Yes |
+| `themeStore` | Active theme, custom themes | Yes |
+| `sidebarStore` | Panel state, width | Yes |
+
+---
+
+## 4. Platform Adapters
+
+### Adapter Interface
+
+```typescript
+export interface PlatformAdapter {
+  name: 'tauri' | 'web';
+
+  // File System
+  fs: {
+    readFile: (path: string) => Promise<string>;
+    writeFile: (path: string, content: string) => Promise<void>;
+    deleteFile: (path: string) => Promise<void>;
+    listDirectory: (path: string) => Promise<FileInfo[]>;
+    exists: (path: string) => Promise<boolean>;
+    watchDirectory?: (path: string, callback: WatchCallback) => () => void;
+  };
+
+  // Conversion
+  convert: {
+    toPdf: (content: string, options: PdfOptions) => Promise<Blob>;
+    toDocx: (content: string, options: DocxOptions) => Promise<Blob>;
+    toHtml: (content: string, options: HtmlOptions) => Promise<string>;
+    batchConvert: (files: string[], format: string) => Promise<ConversionResult[]>;
+  };
+
+  // Capabilities
+  capabilities: {
+    hasPandoc: boolean;
+    hasFfmpeg: boolean;
+    hasLibreOffice: boolean;
+    hasDirectFs: boolean;
+    hasSystemNotifications: boolean;
+  };
+}
+```
+
+### Platform Detection
+
+```typescript
+// Auto-detect platform at startup
+const isTauri = typeof window !== 'undefined' &&
+                '__TAURI__' in window;
+
+export const adapter: PlatformAdapter = isTauri
+  ? tauriAdapter
+  : webAdapter;
+```
+
+### Capability Differences
+
+| Feature | Tauri (Desktop) | Web (PWA) |
+|---------|-----------------|-----------|
+| File System | Direct access | IndexedDB + File System Access API |
+| PDF Export | Pandoc (native) | WASM converter |
+| DOCX Export | Pandoc (native) | Limited/not available |
+| Media Conversion | FFmpeg (native) | Cloud API or limited |
+| File Watching | Native events | Not available |
+| Offline | Always | Service Worker |
+
+---
+
+## 5. Build Configuration
+
+### Vite Configuration
+
+- Target: ESNext
+- Minifier: esbuild
+- Code splitting by vendor chunks
+- Source maps enabled
+
+### Tailwind Configuration
+
+- Dark mode: `class` strategy
+- Custom colors using CSS variables
+- Custom font families (JetBrains Mono, Inter)
+- Tailwindcss-animate plugin
+
+### TypeScript Configuration
+
+- Target: ES2022
+- Strict mode enabled
+- All strict checks enabled
+- Path aliases (`@/*`)
+
+### Bundle Sizes (Estimated)
+
+| Chunk | Size (gzipped) |
+|-------|----------------|
+| `vendor-react` | ~12KB |
+| `vendor-editor` | ~45KB |
+| `vendor-markdown` | ~35KB |
+| `vendor-ui` | ~15KB |
+| `app` (your code) | ~30KB |
+| **Total PWA** | **~137KB** |
+| Tauri desktop | ~5-10MB (with WebView) |
+
+---
+
+## 6. Tauri Backend (Rust)
+
+### IPC Commands
+
+**File System:**
+- `read_file` - Read file content
+- `write_file` - Write file content
+- `delete_file` - Delete file
+- `list_directory` - List directory contents
+- `path_exists` - Check path existence
+- `watch_directory` - Watch for file changes
+
+**Conversion:**
+- `to_pdf` - Convert to PDF via Pandoc
+- `to_docx` - Convert to DOCX via Pandoc
+- `to_html` - Convert to HTML via Pandoc
+- `batch_convert` - Batch conversion
+
+**System:**
+- `check_dependencies` - Check for Pandoc, FFmpeg, LibreOffice
+- `get_config_dir` - Get config directory path
+
+### Security Comparison
+
+| Aspect | Electron (Current) | Tauri |
+|--------|-------------------|-------|
+| `nodeIntegration` | `true` (CVE) | Not possible |
+| `contextIsolation` | `false` (CVE) | Always enforced |
+| Bundle size | ~150MB | ~5-10MB |
+| Memory usage | Higher | Lower |
+| IPC security | Manual whitelist | Compile-time verified |
+
+---
+
+## 7. PWA Configuration
+
+### Web App Manifest
+
+- Name: Markdown Converter
+- Display: Standalone
+- Theme color: #5661b3
+- File handlers for .md, .markdown, .txt
+- Share target for receiving shared content
+
+### Service Worker
+
+- Cache-first for static assets
+- Network-first for API calls
+- Stale-while-revalidate for dynamic content
+- Automatic update detection
+
+### IndexedDB Storage
+
+**Stores:**
+- `files` - Offline file storage
+- `settings` - User preferences
+- `templates` - Custom templates
+
+### PWA Features
+
+| Feature | Implementation |
+|---------|---------------|
+| Offline support | Service Worker + IndexedDB |
+| Install prompt | Web App Manifest |
+| File handling | File System Access API (Chrome) |
+| Share target | Share Target API |
+| Background sync | Background Sync API |
+
+---
+
+## 8. Migration Plan
+
+### Timeline: 8 Weeks
+
+**Phase 1: Foundation (Week 1-2)**
+- Initialize new repo
+- Setup Vite + React + TypeScript
+- Configure Tailwind + Shadcn/ui
+- Setup Zustand stores
+- Create platform adapter interfaces
+- Setup Tauri project structure
+
+**Phase 2: Core Editor (Week 3-4)**
+- CodeMirrorEditor component
+- MarkdownPreview component
+- SplitPane layout
+- Theme system
+- Tab management
+- Keyboard shortcuts
+
+**Phase 3: Sidebar & Panels (Week 5)**
+- Sidebar container
+- ExplorerPanel
+- GitPanel
+- SnippetsPanel
+- TemplatesPanel
+- Bottom panel
+
+**Phase 4: Platform Adapters (Week 6)**
+- Web adapter implementation
+- Tauri adapter implementation
+- File system operations
+- PDF conversion
+- Capability detection
+
+**Phase 5: Export & Conversion (Week 7)**
+- ExportDialog
+- BatchConvertDialog
+- UniversalConverterDialog
+- ImageConverterDialog
+- AudioConverterDialog
+- VideoConverterDialog
+- PDF Editor Dialog
+
+**Phase 6: PWA & Polish (Week 8)**
+- Service Worker setup
+- Web App Manifest
+- IndexedDB storage
+- Offline mode indicator
+- Settings persistence
+- Accessibility audit
+- Performance optimization
+
+### Parallel Development Strategy
+
+```
+Current Electron App (v4.x)     New React+Tauri App (v5.0)
+        │                               │
+        │  Bug fixes only               │  Active development
+        │  Security patches             │  Feature migration
+        ▼                               ▼
+   Stable release  ────────────>  Beta release
+   (maintained)                    (new features)
+```
+
+---
+
+## 9. Design Decisions Summary
+
+| Decision | Choice | Rationale |
+|----------|--------|-----------|
+| Code Structure | Single repo with platform adapters | Lightest weight, clean separation |
+| State Management | Zustand | Minimal (~1KB), simple API |
+| UI Library | Shadcn/ui + Tailwind | Copy-paste ownership, excellent DX |
+| Build Tool | Vite | Industry standard, fast HMR |
+| TypeScript | Strict mode | Maximum type safety |
+| Desktop Features | Hybrid (WASM core, desktop advanced) | Best of both worlds |
+| Migration | Parallel development | Zero disruption to stable release |
+
+---
+
+## 10. Success Criteria
+
+- [ ] All core editor features functional on both Tauri and PWA
+- [ ] Bundle size under 150KB for PWA
+- [ ] All 13 themes migrated and working
+- [ ] Export to PDF works on both platforms
+- [ ] Offline mode fully functional in PWA
+- [ ] WCAG 2.1 AA accessibility compliance
+- [ ] TypeScript strict mode with no `any` types
+- [ ] All IPC channels have TypeScript types
+- [ ] Security audit passes with no critical issues
+
+---
+
+## Appendix: Dependencies
+
+### Production Dependencies
+
+- `react` - UI library
+- `react-dom` - React DOM renderer
+- `zustand` - State management
+- `@radix-ui/react-*` - Headless UI primitives
+- `@codemirror/*` - Code editor
+- `marked` - Markdown parser
+- `highlight.js` - Syntax highlighting
+- `mermaid` - Diagram rendering
+- `dompurify` - HTML sanitization
+- `class-variance-authority` - Component variants
+- `clsx` + `tailwind-merge` - Class utilities
+- `lucide-react` - Icons
+
+### Development Dependencies
+
+- `@tauri-apps/cli` - Tauri CLI
+- `typescript` - TypeScript compiler
+- `vite` - Build tool
+- `tailwindcss` - CSS framework
+- `eslint` - Linting
+- `prettier` - Formatting
+
+---
+
+*Document generated: 2026-03-15*
+*Next step: Invoke writing-plans skill to create detailed implementation plan*

docs/plans/2026-03-24-modal-system-design.md

@@ -0,0 +1,202 @@
+# Modal System Design
+
+**Date:** 2026-03-24
+**Version:** 4.0.0
+**Status:** Approved
+
+## Overview
+
+Replace the existing dialog implementations with a unified modal system that provides:
+- Glassmorphism backdrop matching app aesthetic
+- Full accessibility (ARIA, focus trap, keyboard navigation)
+- Smooth fade + scale animations
+- Consistent API via `ModalManager` class
+
+## Decisions Made
+
+| Decision | Choice | Rationale |
+|----------|--------|-----------|
+| Architecture | Unified `ModalManager` class | Cleaner, consistent behavior across all modals |
+| Backdrop style | Glassmorphism | Matches existing app design language |
+| Focus management | Focus first interactive element | Standard, predictable behavior |
+| Animation | Fade + scale (95% → 100%) | Modern, subtle effect |
+| Implementation | Custom (not native `<dialog>`) | Full control, no polyfill concerns |
+
+## Architecture
+
+### File Structure
+
+```
+src/
+├── utils/
+│   └── ModalManager.js    # Core modal logic (~150 lines)
+├── styles/
+│   └── modal.css          # Unified modal styles (~200 lines)
+└── index.html             # Updated dialog markup
+```
+
+### ModalManager Class
+
+```javascript
+class ModalManager {
+  constructor(element, options = {})
+  open()                    // Show modal with animation
+  close()                   // Hide modal with animation
+  destroy()                 // Cleanup event listeners
+  on(event, callback)       // Event subscription
+
+  // Internal
+  #createBackdrop()         // Create glassmorphism backdrop
+  #trapFocus()              // Manage focus within modal
+  #handleKeydown(e)         // Escape key handler
+  #getFocusableElements()   // Query focusable children
+}
+```
+
+### Events
+
+- `open` — Fired after open animation completes
+- `close` — Fired after close animation completes
+
+## CSS Design
+
+### Variables (from tokens.css)
+
+```css
+--z-modal: 200;
+--transition-normal: 200ms cubic-bezier(0.4, 0, 0.2, 1);
+--shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
+--radius-lg: 0.5rem;
+```
+
+### Backdrop
+
+```css
+.modal-backdrop {
+  position: fixed;
+  inset: 0;
+  background: rgba(0, 0, 0, 0.4);
+  backdrop-filter: blur(4px);
+  -webkit-backdrop-filter: blur(4px);
+  z-index: var(--z-modal);
+}
+```
+
+### Modal Container
+
+```css
+.modal {
+  position: fixed;
+  inset: 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  z-index: calc(var(--z-modal) + 1);
+  opacity: 0;
+  visibility: hidden;
+  transition: opacity var(--transition-normal),
+              visibility var(--transition-normal);
+}
+
+.modal.open {
+  opacity: 1;
+  visibility: visible;
+}
+```
+
+### Modal Content (with animation)
+
+```css
+.modal-content {
+  background: hsl(var(--background));
+  border-radius: var(--radius-lg);
+  box-shadow: var(--shadow-xl);
+  max-width: 90vw;
+  max-height: 90vh;
+  overflow: hidden;
+  transform: scale(0.95);
+  transition: transform var(--transition-normal);
+}
+
+.modal.open .modal-content {
+  transform: scale(1);
+}
+```
+
+## HTML Structure
+
+All dialogs convert to unified structure:
+
+```html
+<div id="export-dialog"
+     class="modal"
+     role="dialog"
+     aria-modal="true"
+     aria-labelledby="export-dialog-title">
+
+  <div class="modal-backdrop" data-close></div>
+
+  <div class="modal-content">
+    <div class="modal-header">
+      <h3 id="export-dialog-title">Export Options</h3>
+      <button class="modal-close" aria-label="Close">&times;</button>
+    </div>
+
+    <div class="modal-body">
+      <!-- Dialog-specific content -->
+    </div>
+
+    <div class="modal-footer">
+      <button class="btn btn-secondary" data-close>Cancel</button>
+      <button class="btn btn-primary">Confirm</button>
+    </div>
+  </div>
+</div>
+```
+
+### Key Attributes
+
+- `role="dialog"` — Screen reader identification
+- `aria-modal="true"` — Prevents screen reader from accessing background
+- `aria-labelledby` — References the dialog title
+- `data-close` — Click handler for closing (backdrop, cancel buttons)
+
+## Accessibility Features
+
+1. **Focus trap** — Tab cycles within modal only
+2. **Focus first element** — Auto-focuses first input/button on open
+3. **Escape key** — Closes modal
+4. **Click outside** — Clicking backdrop closes modal
+5. **Focus restoration** — Returns focus to trigger element on close
+6. **ARIA attributes** — Proper screen reader support
+
+## Dialogs to Migrate
+
+| Dialog ID | Current Class | Complexity |
+|-----------|--------------|------------|
+| `find-dialog` | `.find-dialog` | Simple |
+| `export-dialog` | `.export-dialog` | Complex (many sections) |
+| `print-preview-overlay` | `.export-dialog` | Medium |
+| `table-generator-dialog` | `.export-dialog` | Simple |
+| `ascii-art-dialog` | `.export-dialog` | Medium |
+| `universal-converter-dialog` | `.export-dialog` | Complex |
+| `batch-dialog` | `.batch-dialog` | Complex |
+| `pdf-editor-dialog` | `.export-dialog` | Complex |
+| `header-footer-dialog` | `.export-dialog` | Medium |
+| `field-picker-dialog` | `.export-dialog` | Simple |
+
+## Migration Steps
+
+1. Create `src/utils/ModalManager.js`
+2. Create `src/styles/modal.css`
+3. Update `index.html` to include new stylesheet
+4. Convert each dialog HTML to new structure
+5. Initialize `ModalManager` instances in `renderer.js`
+6. Remove old CSS from `styles.css`
+7. Test all dialogs
+
+## Out of Scope
+
+- Modal nesting (stacked modals) — can be added later if needed
+- Animated backdrop (currently static blur)
+- Modal size variants (small/large/fullscreen) — can use inline styles

docs/plans/2026-03-24-v4-enhancement-flutter-design.md

@@ -0,0 +1,326 @@
+# V4 Enhancement + Flutter Exploration Design
+
+**Date:** 2026-03-24
+**Status:** Approved
+**Approach:** Incremental V4 Enhancement + Flutter Spike (70/30 split)
+
+---
+
+## Executive Summary
+
+This design outlines a two-track approach:
+1. **V4 Enhancement (70%)**: Fix critical bugs, optimize performance, add platform adapters, improve UI patterns
+2. **Flutter Exploration (30%)**: Build proof-of-concept for cross-platform evaluation (Windows, Mobile, Web)
+
+---
+
+## Goals & Scope
+
+### Primary Goals
+1. **Fix critical bug**: PDF and markdown multitab functionality
+2. **Performance improvements**: Faster startup, smoother editing, responsive preview
+3. **Architecture improvements**: Platform adapters, cleaner state management
+4. **Flutter research**: Proof-of-concept for cross-platform evaluation
+
+### Out of Scope
+- Full V5 migration
+- Complete UI redesign
+- New features (focus on optimization)
+
+### Success Criteria
+
+| Metric | Current | Target |
+|--------|---------|--------|
+| Startup time | ~3-5s | <2s |
+| Editor typing latency | Noticeable lag | <16ms |
+| Preview render (1MB file) | ~500ms | <200ms |
+| Memory usage | ~300MB | <200MB |
+| Bundle size | ~150MB | <100MB |
+
+---
+
+## Section 1: V4 Critical Fixes & Performance Optimizations
+
+### 1.1 Fix: PDF/Markdown Multitab Bug
+
+**Location:** `src/renderer.js` (TabManager class)
+
+**Investigation areas:**
+- `switchToTab()` - ensure proper state preservation
+- `closeTab()` - ensure EditorView cleanup
+- Add tab type tracking (markdown vs pdf)
+- Isolate PDF viewer state from editor state
+
+### 1.2 Startup Performance Optimizations
+
+| Optimization | Implementation | Expected Gain |
+|--------------|----------------|---------------|
+| Defer Mermaid | Load only when diagram detected | ~500ms |
+| Defer PDF.js | Load on first PDF open | ~800ms |
+| Lazy load themes | Load active theme only | ~200ms |
+| Lazy sidebar panels | Load panel code when sidebar opens | ~300ms |
+| Preload optimization | Remove unused IPC channels | ~100ms |
+
+**Lazy loading pattern:**
+```javascript
+// Current (loads everything upfront)
+const { dialog } = require('@electron/remote');
+
+// Optimized (load on demand)
+let _dialog;
+function getDialog() {
+  if (!_dialog) _dialog = require('@electron/remote').dialog;
+  return _dialog;
+}
+```
+
+### 1.3 Editor Performance
+
+| Issue | Solution |
+|-------|----------|
+| Typing lag with large files | Debounce preview updates (300ms) |
+| Syntax highlight overhead | Use highlight.js lazy mode |
+| Memory leaks | Clean up EditorView on tab close |
+| Theme switching lag | Pre-compile theme CSS |
+
+### 1.4 Preview Rendering
+
+| Issue | Solution |
+|-------|----------|
+| Mermaid slow | Render on-demand, cache results |
+| Full re-render on keystroke | Debounced incremental updates |
+| Large documents | Viewport rendering (visible portion only) |
+
+---
+
+## Section 2: Platform Adapter Pattern
+
+### 2.1 Architecture
+
+```
+src/
+├── adapters/
+│   ├── index.js              # Auto-detects and exports adapter
+│   ├── types.js              # Interface definitions (JSDoc)
+│   │
+│   ├── electron/             # Current Electron implementation
+│   │   ├── index.js          # Exports electronAdapter
+│   │   ├── fs.js             # File system operations
+│   │   ├── convert.js        # Pandoc, FFmpeg conversions
+│   │   ├── pdf.js            # PDF operations
+│   │   └── system.js         # System info, dialogs, notifications
+│   │
+│   └── mock/                 # For testing
+│       └── index.js          # Mock adapter for unit tests
+```
+
+### 2.2 Adapter Interface
+
+```javascript
+/**
+ * @typedef {Object} PlatformAdapter
+ * @property {'electron'} name
+ * @property {FileSystemAdapter} fs
+ * @property {ConversionAdapter} convert
+ * @property {PdfAdapter} pdf
+ * @property {SystemAdapter} system
+ */
+
+/**
+ * @typedef {Object} FileSystemAdapter
+ * @property {(path: string) => Promise<string>} readFile
+ * @property {(path: string, content: string) => Promise<void>} writeFile
+ * @property {(path: string) => Promise<void>} deleteFile
+ * @property {(path: string) => Promise<FileInfo[]>} listDirectory
+ * @property {(path: string) => Promise<boolean>} exists
+ */
+```
+
+### 2.3 Migration Strategy
+
+| Phase | What | Files Affected |
+|-------|------|----------------|
+| 1 | Create adapter structure | New files only |
+| 2 | Migrate file operations | `renderer.js`, `sidebar/*.js` |
+| 3 | Migrate conversions | Export dialogs |
+| 4 | Migrate PDF operations | PDF viewer |
+| 5 | Remove old IPC calls | `preload.js` cleanup |
+
+---
+
+## Section 3: UI Improvements (Shadcn/ui Patterns)
+
+### 3.1 Design Token System
+
+```css
+/* src/styles/tokens.css */
+
+:root {
+  /* Colors - Light mode */
+  --background: 0 0% 100%;
+  --foreground: 222.2 84% 4.9%;
+  --primary: 227 44% 52%;
+  --primary-foreground: 210 40% 98%;
+  --secondary: 210 40% 96.1%;
+  --secondary-foreground: 222.2 47.4% 11.2%;
+  --muted: 210 40% 96.1%;
+  --muted-foreground: 215.4 16.3% 46.9%;
+  --destructive: 0 84.2% 60.2%;
+  --border: 214.3 31.8% 91.4%;
+  --ring: 227 44% 52%;
+
+  /* Spacing & Radii */
+  --radius: 0.5rem;
+}
+```
+
+### 3.2 Component Improvements
+
+| Component | Current Issue | Fix |
+|-----------|---------------|-----|
+| Buttons | Inconsistent hover/focus | Use `.btn` with variants |
+| Dialogs | Missing focus trap | Add focus trap, Escape key, aria-modal |
+| Tabs | No keyboard navigation | Add arrow key nav, aria-selected |
+| Sidebar | No collapse animation | CSS transitions |
+| Dropdowns | Missing click-outside | Add proper event handling |
+
+### 3.3 Accessibility Improvements
+
+- Focus states with `:focus-visible`
+- Skip to content link
+- ARIA labels on interactive elements
+- Keyboard navigation for all components
+
+---
+
+## Section 4: Flutter Exploration (30% Effort)
+
+### 4.1 Flutter Project Structure
+
+```
+markdown-converter-flutter/
+├── lib/
+│   ├── main.dart
+│   ├── app.dart
+│   ├── core/
+│   │   ├── theme/
+│   │   └── constants.dart
+│   ├── features/
+│   │   ├── editor/
+│   │   ├── preview/
+│   │   └── tabs/
+│   ├── services/
+│   │   ├── file_service.dart
+│   │   ├── export_service.dart
+│   │   └── platform_service.dart
+│   └── adapters/
+│       ├── file_adapter.dart
+│       ├── file_adapter_mobile.dart
+│       ├── file_adapter_web.dart
+│       └── file_adapter_desktop.dart
+├── pubspec.yaml
+├── windows/
+├── web/
+└── lib/
+```
+
+### 4.2 Key Dependencies
+
+```yaml
+dependencies:
+  flutter_markdown: ^0.7.0
+  flutter_code_editor: ^0.3.0
+  provider: ^6.1.0
+  file_picker: ^8.0.0
+  path_provider: ^2.1.0
+  pdf: ^3.10.0
+  printing: ^5.12.0
+```
+
+### 4.3 Prototype Features
+
+| Feature | Priority |
+|---------|----------|
+| Basic markdown editor | Must have |
+| Live preview | Must have |
+| Light/dark theme | Must have |
+| Tab management | Should have |
+| File open/save | Should have |
+| PDF export | Nice to have |
+| Windows exe build | Must have |
+| Web build | Must have |
+| Mobile build | Should have |
+
+### 4.4 Evaluation Criteria
+
+| Metric | Target |
+|--------|--------|
+| Windows exe size | <50MB |
+| Web initial load | <500KB |
+| Cold start time | <2s |
+| Editor typing latency | <16ms |
+
+### 4.5 Flutter vs Tauri Comparison
+
+| Aspect | Flutter | Tauri + React |
+|--------|---------|---------------|
+| Mobile support | ✅ Excellent | ❌ Requires separate app |
+| Web performance | ⚠️ Good, larger | ✅ Excellent, small |
+| Desktop bundle | ⚠️ ~30-50MB | ✅ ~5-10MB |
+| Native feel | ⚠️ Custom rendering | ✅ System WebView |
+| Code reuse | ✅ 100% shared | ⚠️ Some platform-specific |
+
+---
+
+## Implementation Timeline
+
+### Phase 1: V4 Critical Fixes (Week 1)
+- Fix PDF/markdown multitab bug
+- Implement startup optimizations
+- Add debounced preview rendering
+
+### Phase 2: Platform Adapters (Week 2)
+- Create adapter structure
+- Migrate file operations
+- Migrate conversions
+
+### Phase 3: UI Improvements (Week 3)
+- Add design tokens
+- Improve component accessibility
+- Add keyboard navigation
+
+### Phase 4: Flutter Prototype (Weeks 2-4, parallel)
+- Set up Flutter project
+- Implement basic editor
+- Build Windows and Web versions
+- Document findings
+
+---
+
+## Risk Mitigation
+
+| Risk | Mitigation |
+|------|------------|
+| Multitab fix causes regressions | Comprehensive test suite before changes |
+| Performance optimizations break features | Incremental changes with benchmarks |
+| Flutter proves unsuitable | 30% effort limit, V4 remains primary |
+| Platform adapter migration too slow | Phased approach, each phase independent |
+
+---
+
+## Success Metrics
+
+- [ ] Multitab functionality working correctly
+- [ ] Startup time < 2 seconds
+- [ ] No perceived editor lag with files < 1MB
+- [ ] Preview renders in < 200ms
+- [ ] Bundle size reduced by 30%+
+- [ ] Platform adapters for fs, convert, pdf implemented
+- [ ] Design tokens applied to all components
+- [ ] Flutter prototype running on Windows + Web
+- [ ] Flutter evaluation documented with recommendation
+
+---
+
+*Document generated: 2026-03-24*
+*Next step: Create detailed implementation plan*

docs/plans/2026-04-06-writers-studio-design.md

@@ -0,0 +1,335 @@
+# Writer's Studio Feature Pack — Design Document
+
+**Date**: 2026-04-06
+**Version**: 4.2.0 target
+**Status**: Approved
+**Scope**: Three cohesive features to transform MarkdownConverter into a writing environment
+
+---
+
+## Overview
+
+The Writer's Studio Feature Pack adds three interconnected features to MarkdownConverter:
+
+1. **Zen Mode** — Distraction-free writing environment with typewriter scrolling
+2. **Document Outline** — Heading hierarchy sidebar panel for navigation
+3. **Writing Analytics** — Real-time readability and vocabulary analysis dashboard
+
+These features work together: Zen Mode creates the environment, Outline provides navigation, Analytics gives insight.
+
+---
+
+## Feature 1: Zen Mode
+
+### Purpose
+
+Transform the app from a multi-tool into a focused writing environment. Inspired by iA Writer, Typora, and Bear.
+
+### New Files
+
+- `src/zen-mode.js` — ZenMode class (~150 lines)
+- `src/styles-zen.css` — Zen mode specific styles (~120 lines)
+
+### Integration Points
+
+- `src/renderer.js` — Initialize ZenMode, register F11 shortcut, add View > Zen Mode menu
+- `src/editor/codemirror-setup.js` — Export typewriter + dimming extensions
+
+### Behavior
+
+**Toggle**: F11, View > Zen Mode, command palette "Toggle Zen Mode"
+**Exit**: Escape key, F11 again
+
+**What hides**:
+- Tab bar
+- Toolbar
+- Sidebar (collapsed)
+- Status bar
+- App header
+
+**What shows**:
+- Editor (full viewport)
+- Floating HUD (bottom-center, semi-transparent)
+
+### Floating HUD
+
+```
+┌─────────────────────────────────────────┐
+│  847 words  •  ~4 min  •  23:45 session │
+│  ████████████████░░░░  85% of 1000      │
+└─────────────────────────────────────────┘
+```
+
+- Word count (from existing status bar logic)
+- Estimated reading time (~200 wpm)
+- Session timer (starts when zen mode activates)
+- Optional progress bar toward word goal
+
+### CodeMirror Extensions
+
+**Typewriter Scroll** (`ViewPlugin`):
+- Listens to `EditorView.update` for selection changes
+- Calls `editor.dispatch({ effects: EditorView.scrollIntoView(pos, { y: 'center' }) })`
+- Smooth scrolling with `scrollBehavior: 'smooth'` in CSS
+
+**Line Dimming** (`ViewPlugin` + `Decoration`):
+- Builds a `DecorationSet` mapping each line to an opacity value
+- Active line: opacity 1.0
+- 1-2 lines away: 0.7
+- 3-4 lines away: 0.5
+- 5+ lines away: 0.3
+- Uses `Decoration.line({ attributes: { style: 'opacity: X' } })`
+
+### Centered Column
+
+CSS applied to `.zen-mode .cm-content`:
+```css
+.zen-mode .cm-content {
+    max-width: 700px;
+    margin: 0 auto;
+    font-size: 18px;
+    line-height: 1.8;
+}
+```
+
+### State Management
+
+- `this.previousState` stores which UI elements were visible before zen mode
+- On exit, restores all elements to their previous visibility
+- Editor content, cursor position, and scroll state are never modified
+
+---
+
+## Feature 2: Document Outline Panel
+
+### Purpose
+
+Provide always-visible heading navigation for documents of any length. The single most-requested navigation feature for multi-section documents.
+
+### New Files
+
+- `src/sidebar/outline-panel.js` — `renderOutlinePanel` function (~100 lines)
+
+### Modified Files
+
+- `src/index.html` — Add outline icon button in sidebar icons strip
+- `src/renderer.js` — Register 'outline' panel, provide editor reference
+
+### Sidebar Integration
+
+Uses existing `SidebarManager.registerPanel()` API:
+```javascript
+sidebarManager.registerPanel('outline', {
+    title: 'Outline',
+    render: (container) => renderOutlinePanel(container, editor, editorContent)
+});
+```
+
+New icon button in sidebar strip (after templates icon):
+```html
+<button class="sidebar-icon" data-panel="outline" title="Outline (Ctrl+Shift+O)">
+    <!-- hierarchy/list icon SVG -->
+</button>
+```
+
+### Parsing Logic
+
+Parse headings from raw markdown content using regex:
+```javascript
+const headingRegex = /^(#{1,6})\s+(.+)$/gm;
+```
+
+Returns array of:
+```javascript
+{ level: 1-6, text: "Heading Text", line: 42 }
+```
+
+Debounced at 300ms to avoid re-parsing on every keystroke.
+
+### UI Structure
+
+```
+┌──────────────────────────────────────────┐
+│  OUTLINE                          ☰      │
+├──────────────────────────────────────────┤
+│  ▸ Introduction                  (H1)    │
+│    ▸ Getting Started             (H2)    │
+│    ▸ Prerequisites               (H2)    │
+│      ▸ Node.js                   (H3) ◄  │
+│    ▸ Installation                (H2)    │
+│  ▸ Features                      (H1)    │
+│    ▸ Editor                      (H2)    │
+│    ▸ Export                      (H2)    │
+├──────────────────────────────────────────┤
+│  9 headings  •  2 H1  •  4 H2  •  3 H3  │
+└──────────────────────────────────────────┘
+```
+
+- Indentation based on heading level (H1 = 0px, H2 = 16px, H3 = 32px, etc.)
+- Current heading highlighted with accent color (◄ indicator)
+- Hover shows full heading text if truncated
+
+### Click-to-Navigate
+
+```javascript
+editor.dispatch({
+    effects: EditorView.scrollIntoView(linePos, { y: 'center' })
+});
+```
+
+Brief highlight animation on the target line (fades out over 500ms).
+
+### Current Heading Sync
+
+On editor update (debounced 100ms):
+1. Get cursor line number
+2. Find the last heading whose line number <= cursor line
+3. Set that heading as active in the outline
+
+### Empty State
+
+When no headings found:
+```
+No headings found
+
+Use # to create headings:
+# Heading 1
+## Heading 2
+### Heading 3
+```
+
+---
+
+## Feature 3: Writing Analytics
+
+### Purpose
+
+Give writers real-time insight into their document's readability, structure, and vocabulary. This is the "surprise" feature most Markdown editors lack.
+
+### New Files
+
+- `src/analytics/writing-analytics.js` — `WritingAnalytics` class (~180 lines)
+- `src/analytics/analytics-panel.js` — `renderAnalyticsPanel` function (~120 lines)
+
+### Integration Points
+
+- `src/renderer.js` — Register Ctrl+Shift+A shortcut, command palette entry, View menu item
+
+### Trigger
+
+- Keyboard: `Ctrl+Shift+A`
+- Command Palette: "Show Writing Analytics"
+- Menu: View > Writing Analytics
+
+### Presentation
+
+Uses existing `ModalManager` to show a modal overlay with analytics dashboard.
+
+```
+┌─────────────────────────────────────────────────────┐
+│  Writing Analytics                              ✕   │
+├─────────────────────────────────────────────────────┤
+│                                                      │
+│  ┌─ Readability ──────────────────────────────────┐ │
+│  │  Flesch Reading Ease:  67.3 (Standard)    ○   │ │
+│  │  Grade Level:          8.2              ○○○●○  │ │
+│  └─────────────────────────────────────────────────┘ │
+│                                                      │
+│  ┌─ Timing ───────────────────────────────────────┐ │
+│  │  Reading Time:   ~4 min                        │ │
+│  │  Speaking Time:  ~6 min                        │ │
+│  └─────────────────────────────────────────────────┘ │
+│                                                      │
+│  ┌─ Structure ────────────────────────────────────┐ │
+│  │  Sentences:  42  •  Paragraphs:  8            │ │
+│  │  Avg Sentence:  14.2 words                     │ │
+│  │  Longest:  38 words ("The quick brown fox...") │ │
+│  └─────────────────────────────────────────────────┘ │
+│                                                      │
+│  ┌─ Vocabulary ───────────────────────────────────┐ │
+│  │  Unique: 312 / 847 words (36.8%)               │ │
+│  │  Top: the(42) and(31) markdown(28) ...         │ │
+│  └─────────────────────────────────────────────────┘ │
+│                                                      │
+│  ┌─ Word Goal ────────────────────────────────────┐ │
+│  │  Target: [1000] words                          │ │
+│  │  ████████████████░░░░  847/1000 (85%)          │ │
+│  └─────────────────────────────────────────────────┘ │
+│                                                      │
+└─────────────────────────────────────────────────────┘
+```
+
+### Metrics Implementation
+
+**Readability (Flesch-Kincaid):**
+```javascript
+// Flesch Reading Ease
+ease = 206.835 - 1.015 * (words / sentences) - 84.6 * (syllables / words);
+
+// Flesch-Kincaid Grade Level
+grade = 0.39 * (words / sentences) + 11.8 * (syllables / words) - 15.59;
+```
+
+**Syllable Estimation:**
+```javascript
+function countSyllables(word) {
+    word = word.toLowerCase().replace(/(?:[^laeiouy]es|ed|[^laeiouy]e)$/, '');
+    word = word.replace(/^y/, '');
+    return word.match(/[aeiouy]{1,2}/g)?.length || 1;
+}
+```
+
+**Reading/Speaking Time:**
+- Reading: 200 words/minute
+- Speaking: 130 words/minute
+
+**Lexical Diversity:**
+- Ratio of unique words to total words (excluding stop words)
+
+**Top Words:**
+- Frequency map, sorted descending, top 10
+- Excludes common stop words (the, a, an, is, are, etc.)
+
+### Word Goal
+
+- Persisted in `electron-store` per document (or global default)
+- Progress bar with percentage
+- Celebration effect when goal is reached (brief confetti animation or green flash)
+
+### Update Cadence
+
+- Re-analyzes on editor content change (debounced at 1000ms)
+- If modal is open, updates live
+- If modal is closed, no computation (zero overhead)
+
+---
+
+## File Summary
+
+| File | Action | Purpose |
+|------|--------|---------|
+| `src/zen-mode.js` | Create | ZenMode class with CM6 extensions |
+| `src/styles-zen.css` | Create | Zen mode styling |
+| `src/sidebar/outline-panel.js` | Create | Outline sidebar panel |
+| `src/analytics/writing-analytics.js` | Create | Analytics computation engine |
+| `src/analytics/analytics-panel.js` | Create | Analytics modal UI |
+| `src/index.html` | Modify | Add outline icon, zen mode button |
+| `src/renderer.js` | Modify | Initialize all three features |
+| `src/editor/codemirror-setup.js` | Modify | Export typewriter + dimming extensions |
+
+## Keyboard Shortcuts
+
+| Shortcut | Feature | Action |
+|----------|---------|--------|
+| F11 | Zen Mode | Toggle on/off |
+| Escape | Zen Mode | Exit (when active) |
+| Ctrl+Shift+O | Outline | Open outline sidebar panel |
+| Ctrl+Shift+A | Analytics | Open analytics modal |
+
+## Dependencies
+
+No new npm dependencies required. All features use:
+- Existing CodeMirror 6 APIs (ViewPlugin, Decoration, scrollIntoView)
+- Existing SidebarManager API
+- Existing ModalManager API
+- Pure JavaScript math for analytics

docs/superpowers/specs/2026-04-14-v5-platform-design.md

@@ -0,0 +1,426 @@
+# MarkdownConverter v5.0 — Platform Design
+
+**Date:** 2026-04-14
+**Status:** Approved
+**Author:** Amit Haridas
+
+## Overview
+
+Transform MarkdownConverter from a monolithic editor into an extensible platform with a plugin system and three feature packs, shipped together as v5.0.
+
+## Subsystems
+
+1. **Plugin System** — Lightweight plugin registry with extension points (sidebar, commands, settings, status bar, export hooks, event bus)
+2. **Writing Studio Plugin** — Manuscript manager, goal tracking, writing sprints, snapshots, smart proofreading
+3. **AI Assistant Plugin** — Multi-provider AI writing assistant (Ollama, LMStudio, GGUF direct with GPU, Anthropic, OpenAI)
+4. **Collaboration Plugin** — Git-based async collaboration, comments/annotations, review requests
+
+## Core Principle
+
+**Existing functionality is never replaced or broken.** The plugin system is additive. All existing keyboard shortcuts, features, and UI remain untouched. Plugin shortcuts use `Ctrl+Alt+` namespace.
+
+---
+
+## 1. Plugin System
+
+### File Structure
+
+```
+src/
+  plugins/
+    plugin-registry.js      # Load, register, lifecycle
+    plugin-api.js            # Base class plugins extend
+    plugin-loader.js         # Discovers and validates manifests
+    built-in/
+      writing-studio/
+        manifest.json
+        index.js
+        panels/
+        components/
+      ai-assistant/
+        manifest.json
+        index.js
+        providers/
+      collaboration/
+        manifest.json
+        index.js
+```
+
+### Manifest Schema
+
+```json
+{
+  "id": "writing-studio",
+  "name": "Writing Studio",
+  "version": "1.0.0",
+  "description": "Manuscript management, goal tracking, writing sprints",
+  "icon": "pen-tool",
+  "extensionPoints": {
+    "sidebar": { "panel": "panels/manuscript-panel.js", "order": 30 },
+    "settings": { "section": "settings/index.js" },
+    "statusBar": { "indicators": ["sprint-timer", "word-goal"] },
+    "commands": [
+      { "id": "start-sprint", "label": "Start Writing Sprint", "shortcut": "Ctrl+Alt+S" },
+      { "id": "take-snapshot", "label": "Take Snapshot", "shortcut": "Ctrl+Alt+N" }
+    ],
+    "exportHooks": {
+      "preExport": "hooks/pre-export.js",
+      "postExport": "hooks/post-export.js"
+    }
+  },
+  "settings": [
+    { "key": "dailyGoal", "type": "number", "default": 1000, "label": "Daily word goal" },
+    { "key": "sprintDuration", "type": "number", "default": 25, "label": "Sprint duration (min)" }
+  ]
+}
+```
+
+### Plugin Lifecycle
+
+1. PluginLoader discovers manifests in `built-in/` + user plugins directory
+2. PluginRegistry validates manifests
+3. Each plugin calls `Plugin.init(context)` receiving scoped API context
+4. Extension points registered (sidebar panels, commands, status bar items)
+5. Plugins activate lazily — sidebar panel loads JS when user clicks tab
+
+### Plugin Context API
+
+Each plugin's `init()` receives:
+
+```javascript
+{
+  sidebar: {
+    registerPanel(id, { icon, title, component })
+  },
+  commands: {
+    register(id, label, handler, shortcut?)
+  },
+  statusBar: {
+    registerIndicator(id, { position, render })
+  },
+  settings: {
+    get(key),                    // plugin-scoped
+    set(key, value),             // auto-persisted via electron-store
+    onChanged(key, callback)
+  },
+  editor: {
+    getContent(),                // current document
+    getSelection(),              // selected text
+    insertAtCursor(text),        // requires opt-in
+    onContentChanged(callback)
+  },
+  events: {
+    on(event, handler),
+    emit(event, data)
+  },
+  exports: {
+    registerPreHook(handler),
+    registerPostHook(handler)
+  },
+  ipc: {
+    invoke(channel, ...args),
+    on(channel, handler)
+  }
+}
+```
+
+### Event Bus Events
+
+Each event has a versioned payload schema. Breaking changes increment the version suffix.
+
+```
+document:opened        → { filePath: string, tabId: string }
+document:saved         → { filePath: string, tabId: string }
+document:changed       → { tabId: string, content: string, wordCount: number }
+editor:selection-changed → { tabId: string, text: string, from: {line,ch}, to: {line,ch} }
+tab:switched           → { tabId: string, filePath: string }
+tab:closed             → { tabId: string, filePath: string }
+export:started         → { format: string, filePath: string }
+export:completed       → { format: string, filePath: string, outputPath: string }
+export:failed          → { format: string, error: string }
+plugin:loaded          → { pluginId: string, version: string }
+plugin:activated       → { pluginId: string }
+plugin:deactivated     → { pluginId: string }
+app:ready              → {}
+app:before-quit        → {}
+```
+
+### Design Rules
+
+- Built-in plugins use the same API as future third-party plugins
+- Lazy activation — sidebar panels don't load until clicked
+- Scoped settings: `plugins.<id>.<key>` in electron-store
+- Plugin commands globally unique — registry rejects duplicate command IDs at load time
+- **Plugin sandboxing**: each plugin handler is wrapped in try/catch. For CPU-intensive operations (AI inference, diff computation), plugins must delegate to main process via IPC. Handlers that block the renderer for >5s trigger a warning notification. Memory-hungry operations (GGUF inference) run in isolated child processes.
+- **Cross-plugin graceful degradation**: plugins check `context.events.hasHandler('ai:analyze')` before emitting cross-plugin requests. If no handler (AI plugin disabled), show a "this feature requires the AI plugin" prompt instead of failing silently. All cross-plugin calls have a 30s timeout with default fallback behavior.
+
+---
+
+## 2. Writing Studio Plugin
+
+### 2A. Manuscript / Project Manager
+
+Folder-based project structure:
+
+```
+~/Manuscripts/
+  my-novel/
+    .project.json          # { title, targets, metadata }
+    01-chapter-one.md
+    02-chapter-two.md
+    characters/
+      protagonist.md
+    research/
+      world-building.md
+    .snapshots/
+      2026-04-14T10-30.json
+```
+
+`.project.json`:
+
+```json
+{
+  "title": "My Novel",
+  "type": "manuscript",
+  "target": { "words": 80000, "deadline": "2026-09-01" },
+  "chapters": [
+    { "file": "01-chapter-one.md", "title": "The Beginning", "status": "draft" }
+  ],
+  "metadata": { "author": "", "genre": "", "synopsis": "" }
+}
+```
+
+Sidebar panel shows project tree with drag-to-reorder, word counts per chapter, target progress bar. "Compile manuscript" exports all chapters as a single document.
+
+### 2B. Goal Tracking & Writing Sprints
+
+- **Status bar**: daily progress bar + sprint timer
+- **Writing sprint**: configurable duration (15/25/30/45/60 min), word count delta, WPM at end
+- **Goal tracking**: daily/weekly word goals, streak tracking, 30-day bar chart
+- **Enhanced analytics**: session tracking, readability scores, productive time-of-day heatmap
+- Data stored in `plugins.writing-studio.history` as date-keyed map
+
+### 2C. Snapshot & Versioning
+
+- `Ctrl+Alt+N` or toolbar button saves snapshot
+- Stored as JSON: `{ timestamp, content, wordCount, cursorPos, label }`
+- Snapshot panel in sidebar: Restore, Diff (side-by-side), auto-snapshot interval
+- Snapshots in `.snapshots/` inside project folder, or app data if no project
+
+### 2D. Smart Proofreading
+
+Delegates to AI plugin via event bus. Writing Studio provides:
+- Right-click context menu: "Check grammar", "Suggest alternatives", "Analyze readability"
+- Inline wavy underline decorations for issues
+- Proofread panel: issues categorized by type with Accept/Dismiss
+
+### Commands
+
+| Command | Shortcut | Action |
+|---------|----------|--------|
+| `start-sprint` | `Ctrl+Alt+S` | Start writing sprint |
+| `stop-sprint` | `Ctrl+Alt+Shift+S` | Stop sprint |
+| `take-snapshot` | `Ctrl+Alt+N` | Save snapshot |
+| `restore-last-snapshot` | `Ctrl+Alt+Z` | Restore latest snapshot |
+| `new-project` | — | Create manuscript project |
+| `compile-manuscript` | `Ctrl+Alt+E` | Export all chapters |
+| `proofread-document` | `Ctrl+Alt+G` | AI proofread |
+
+---
+
+## 3. AI Assistant Plugin
+
+### Provider Architecture
+
+```
+AI Plugin
+  ├── Provider Interface
+  │     ├── complete(prompt, options) → string
+  │     ├── stream(prompt, options) → AsyncIterable
+  │     └── analyze(text, type) → AnalysisResult
+  │
+  ├── Providers
+  │     ├── OllamaProvider      — localhost:11434
+  │     ├── LMStudioProvider    — localhost:1234/v1
+  │     ├── GGUFProvider         — direct llama.cpp with GPU support
+  │     ├── AnthropicProvider    — Claude API
+  │     └── OpenAIProvider       — GPT API
+  │
+  └── Features
+        ├── Grammar/style check
+        ├── Inline auto-complete
+        ├── AI chat panel (sidebar)
+        ├── Document analysis
+        └── Smart commands (command palette)
+```
+
+### Provider Details
+
+**Ollama:** `GET /api/tags` for models, `POST /api/generate` and `POST /api/chat` for inference.
+
+**LMStudio:** OpenAI-compatible API at `localhost:1234/v1`. `GET /v1/models`, standard chat completion format, SSE streaming.
+
+**GGUF Direct (with GPU):**
+- Ships bundled llama.cpp binaries per platform (CUDA, Vulkan, Metal, CPU variants)
+- Auto-detects GPU: CUDA (nvidia-smi), Vulkan driver, Metal (macOS)
+- GPU layer offloading: configurable, auto-suggests based on VRAM vs model size
+- Settings: GPU backend selection, layer count, context length, thread count
+- "Keep model loaded" option for faster repeated requests
+- WASM fallback for sandboxed environments (CPU-only)
+- External binary path for advanced users with custom builds
+- **Process isolation**: llama.cpp runs as a spawned child process (not in main process). If it crashes, detected via exit handler, auto-restarted with notification. GPU memory freed on crash. App remains stable.
+- Process management: spawn in server mode on localhost ephemeral port, clean up on app quit or model unload
+
+**Cloud (Anthropic/OpenAI):**
+- API key stored encrypted via electron safeStorage
+- Token usage tracking with estimated cost
+- Rate limit awareness with request queueing and backoff
+
+### IPC Design
+
+All provider HTTP requests go through main process:
+- No CORS issues
+- API keys never in renderer
+- Main process enforces rate limiting
+- GGUF inference in isolated child process
+
+**Request/response lifecycle:**
+```
+Renderer → ipc.invoke('ai:complete') → Main → HTTP to provider → result → Renderer
+```
+
+**Streaming lifecycle with error handling:**
+```
+Renderer → ipc.invoke('ai:stream', { requestId, prompt })
+         ← Main assigns requestId, returns { requestId }
+         ← ipc.on('ai:chunk', { requestId, text }) — repeated
+         ← ipc.on('ai:done', { requestId }) — success
+         ← ipc.on('ai:error', { requestId, error }) — failure
+
+// Cancellation
+Renderer → ipc.invoke('ai:cancel', { requestId })
+         ← Main aborts HTTP request, emits 'ai:done'
+
+// Orphan cleanup: if renderer disconnects (crash/close),
+// main process detects via 'render-view-deleted' and aborts all active streams.
+// Heartbeat: if no chunk received in 30s, main emits 'ai:error' with timeout.
+```
+
+### Features
+
+1. **Inline suggestions**: ghost text after configurable delay, Tab to accept, Esc to dismiss
+2. **AI chat panel**: sidebar conversation, "Insert" / "Replace selection" buttons
+3. **Document analysis**: grammar, style, tone, with accept/reject per suggestion
+4. **Smart commands**: summarize, generate outline, find inconsistencies, translate, explain code
+
+### Privacy
+
+- Local-first: default provider is Ollama
+- No telemetry: requests go direct to provider
+- Content gating: exclude file types from AI
+- Status bar shows "AI: processing..." with cancel option
+- Cloud usage stats in settings (tokens, cost)
+
+### Cross-Plugin Integration
+
+```javascript
+// Writing Studio calls AI Plugin
+context.events.emit('ai:analyze', { text, type: 'grammar', callback });
+```
+
+---
+
+## 4. Collaboration Plugin
+
+### 4A. Enhanced Git Panel
+
+Upgrades to existing git panel:
+- Remote management (add/remove remotes, push/pull)
+- Branch list and switching
+- Commit history with diff viewer (side-by-side or unified)
+- Conflict resolution UI (accept-ours/accept-theirs/per-edit)
+
+### 4B. Shared Repository Workflow
+
+1. Writer A creates project + initializes git + pushes to shared repo
+2. Writer B clones repo from within MarkdownConverter
+3. Both write on their own branches
+4. Writer A creates review request (simplified PR)
+
+Review request: changed files, word count diff, commit messages. Reviewer can approve, request changes, leave inline comments. Reviews are git branches + comments as git notes.
+
+### 4C. Comments & Annotations
+
+Inline comments stored as JSON in `.comments/` directory (git-tracked):
+```json
+{
+  "id": "uuid",
+  "file": "03-chapter-three.md",
+  "anchor": {
+    "contextBefore": "The hero looked at the horizon and said,",
+    "selectedText": "I will not go quietly into that dark night",
+    "contextAfter": "He turned to face the army alone."
+  },
+  "line": 142,
+  "text": "This dialogue feels unnatural",
+  "author": "amit",
+  "timestamp": "2026-04-14T14:30:00Z",
+  "replies": [],
+  "resolved": false
+}
+```
+
+- **Anchor-based positioning**: comments store `contextBefore`, `selectedText`, and `contextAfter` (not absolute byte offsets). On file change, re-anchor by searching for the context text. If context no longer matches, mark comment as "detached" and show a warning. Falls back to `line` number as rough position.
+- Highlighted text in editor with tooltip on hover
+- Comment panel in sidebar: all unresolved comments across files
+- Resolution workflow: add → address → reply → resolve
+- Resolved comments dim but stay visible
+
+### 4D. Change Notifications
+
+- Status bar indicator: `↓ 3 new commits`
+- Click to see changes, one-click pull
+- Conflicts trigger resolution UI
+- Push button only when local commits ahead of remote
+
+### 4E. Offline-First
+
+All writing happens locally. Git is the sync mechanism. No internet required for writing, commenting, snapshots, or sprints. Push/pull on user action or auto-sync setting.
+
+### Commands
+
+| Command | Shortcut | Action |
+|---------|----------|--------|
+| `collab:commit` | `Ctrl+Shift+G` | Commit with message |
+| `collab:push` | — | Push current branch |
+| `collab:pull` | — | Pull from remote |
+| `collab:add-comment` | `Ctrl+Alt+C` | Comment on selection |
+| `collab:next-comment` | `F8` | Next unresolved comment |
+| `collab:prev-comment` | `Shift+F8` | Previous comment |
+| `collab:create-review` | — | Create review request |
+
+### Cross-Plugin Integration
+
+```javascript
+context.events.emit('snapshot:created', { file, snapshotId });
+context.events.on('project:chapter-opened', (chapter) => { /* load comments */ });
+context.events.on('comment:added', (comment) => { /* AI could suggest fix */ });
+```
+
+---
+
+## Bundle Size Impact
+
+- llama.cpp binaries: ~15MB per GPU variant. Only target platform shipped. GPU variants (CUDA/Vulkan/Metal) downloaded on demand if user enables GGUF direct loading — not bundled by default. Only CPU fallback bundled (~15MB).
+- Plugin system core: ~30KB
+- Each built-in plugin: ~50-100KB
+- Diff library (jsdiff): ~15KB
+- Total estimated increase: ~20-30MB (core), additional ~30-50MB per GPU variant (lazy download)
+
+## Testing Strategy
+
+- Plugin system: unit tests for registry, loader, context API mocking
+- Each plugin: isolated unit tests, integration tests via plugin context
+- AI provider tests: mock HTTP responses, test streaming parsing
+- Git tests: use test repository fixture
+- E2E: verify plugin loading doesn't break existing features

eslint.config.js

@@ -0,0 +1,112 @@
+/**
+ * ESLint Configuration for PanConverter
+ * Uses flat config format (ESLint 9+)
+ */
+
+module.exports = [
+  {
+    // Global ignores
+    ignores: [
+      'node_modules/**',
+      'dist/**',
+      'coverage/**',
+      '*.min.js'
+    ]
+  },
+  {
+    // JavaScript files
+    files: ['**/*.js'],
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: 'module',
+      globals: {
+        // Node.js
+        require: 'readonly',
+        module: 'readonly',
+        exports: 'readonly',
+        __dirname: 'readonly',
+        __filename: 'readonly',
+        process: 'readonly',
+        Buffer: 'readonly',
+        console: 'readonly',
+        setTimeout: 'readonly',
+        setInterval: 'readonly',
+        clearTimeout: 'readonly',
+        clearInterval: 'readonly',
+        // Browser
+        window: 'readonly',
+        document: 'readonly',
+        localStorage: 'readonly',
+        alert: 'readonly',
+        prompt: 'readonly',
+        confirm: 'readonly',
+        Event: 'readonly',
+        CustomEvent: 'readonly',
+        HTMLElement: 'readonly',
+        MutationObserver: 'readonly',
+        TextEncoder: 'readonly',
+        FileReader: 'readonly',
+        requestAnimationFrame: 'readonly',
+        cancelAnimationFrame: 'readonly',
+        navigator: 'readonly',
+        location: 'readonly',
+        fetch: 'readonly',
+        URL: 'readonly',
+        Blob: 'readonly',
+        Image: 'readonly',
+        DragEvent: 'readonly',
+        ClipboardEvent: 'readonly',
+        KeyboardEvent: 'readonly',
+        MouseEvent: 'readonly',
+        NodeList: 'readonly',
+        HTMLInputElement: 'readonly',
+        HTMLTextAreaElement: 'readonly',
+        getComputedStyle: 'readonly',
+        // Electron
+        electronAPI: 'readonly',
+        // Libraries
+        marked: 'readonly',
+        DOMPurify: 'readonly',
+        hljs: 'readonly',
+        mermaid: 'readonly',
+        // Node.js global object
+        global: 'writable',
+        // Jest
+        jest: 'readonly',
+        describe: 'readonly',
+        test: 'readonly',
+        it: 'readonly',
+        expect: 'readonly',
+        beforeEach: 'readonly',
+        afterEach: 'readonly',
+        beforeAll: 'readonly',
+        afterAll: 'readonly'
+      }
+    },
+    rules: {
+      // Error prevention
+      'no-unused-vars': ['warn', { argsIgnorePattern: '^_' }],
+      'no-undef': 'error',
+      'no-console': 'off', // Allow console for Electron apps
+
+      // Code quality
+      'eqeqeq': ['warn', 'always'],
+      'no-var': 'warn',
+      'prefer-const': 'warn',
+
+      // Style (handled by Prettier)
+      'semi': 'off',
+      'quotes': 'off',
+      'indent': 'off',
+
+      // Async handling
+      'no-async-promise-executor': 'warn',
+      'require-await': 'off',
+
+      // Security
+      'no-eval': 'error',
+      'no-implied-eval': 'error',
+      'no-new-func': 'error'
+    }
+  }
+];

jest.config.js

@@ -0,0 +1,61 @@
+/**
+ * Jest Configuration for PanConverter
+ * @version 2.2.0
+ */
+
+module.exports = {
+  // Test environment
+  testEnvironment: 'jsdom',
+
+  // Root directory
+  rootDir: '.',
+
+  // Test file patterns
+  testMatch: [
+    '**/tests/**/*.test.js',
+    '**/tests/**/*.spec.js'
+  ],
+
+  // Coverage configuration
+  collectCoverageFrom: [
+    'src/**/*.js',
+    '!src/main.js', // Main process needs electron-mock
+    '!src/renderer.js', // Large renderer file with duplicate declarations
+    '!src/preload.js', // Electron preload requires contextBridge
+    '!**/node_modules/**'
+  ],
+
+  // Coverage thresholds (raised with expanded test suite)
+  coverageThreshold: {
+    global: {
+      branches: 10,
+      functions: 15,
+      lines: 15,
+      statements: 15
+    }
+  },
+
+  // Transform settings (no transpilation needed for vanilla JS)
+  transform: {},
+
+  // Module paths
+  moduleDirectories: ['node_modules', 'src'],
+
+  // Setup files
+  setupFilesAfterEnv: ['<rootDir>/tests/setup.js'],
+
+  // Ignore patterns
+  testPathIgnorePatterns: [
+    '/node_modules/',
+    '/dist/'
+  ],
+
+  // Verbose output
+  verbose: true,
+
+  // Clear mocks between tests
+  clearMocks: true,
+
+  // Reset modules between tests
+  resetModules: true
+};

package.json

@@ -1,47 +1,106 @@
 {
-  "name": "pan-converter",
+  "name": "markdown-converter",
-  "version": "1.6.0",
+  "version": "4.4.3",
-  "description": "Cross-platform Markdown editor and converter using Pandoc",
+  "description": "Professional Markdown editor and universal file converter with PDF editing, batch processing, and syntax highlighting",
   "main": "src/main.js",
   "scripts": {
     "start": "electron .",
-    "test": "echo \"Error: no test specified\" && exit 1",
+    "test": "jest",
+    "test:watch": "jest --watch",
+    "test:coverage": "jest --coverage",
+    "lint": "eslint src tests",
+    "lint:fix": "eslint src tests --fix",
+    "format": "prettier --write src tests",
+    "format:check": "prettier --check src tests",
     "build": "electron-builder",
-    "build:win": "cross-env CSC_LINK=code-signing-cert.pfx CSC_KEY_PASSWORD=PanConverter2024! electron-builder --win",
+    "build:win": "electron-builder --win",
+    "build:win-signed": "cross-env CSC_LINK=code-signing-cert.pfx electron-builder --win",
     "build:win-unsigned": "cross-env CSC_IDENTITY_AUTO_DISCOVERY=false electron-builder --win",
+    "create-cert": "powershell -ExecutionPolicy Bypass -File scripts/create-selfsigned-cert.ps1",
     "build:mac": "electron-builder --mac",
     "build:linux": "electron-builder --linux",
+    "build:linux-ci": "electron-builder --linux deb AppImage",
+    "build:local": "electron-builder --linux --win",
     "dist": "electron-builder --publish=never",
     "dist:all": "electron-builder -mwl",
+    "download-tools": "node scripts/download-tools.js",
     "generate-icons": "node scripts/generate-icons.js"
   },
   "keywords": [
     "markdown",
     "pandoc",
     "converter",
-    "editor"
+    "editor",
+    "pdf",
+    "audio",
+    "video",
+    "image"
   ],
-  "author": "Amit Haridas <amit.wh@gmail.com>",
+  "author": "ConcreteInfo <amit.wh@gmail.com>",
   "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/amitwh/markdown-converter"
+  },
   "devDependencies": {
+    "@testing-library/dom": "^10.4.1",
     "cross-env": "^10.0.0",
-    "electron": "^37.4.0",
+    "electron": "^41.1.1",
     "electron-builder": "^26.0.12",
+    "eslint": "^9.39.2",
+    "eslint-config-prettier": "^10.1.8",
+    "eslint-plugin-prettier": "^5.5.4",
+    "jest": "^30.2.0",
+    "jest-environment-jsdom": "^30.2.0",
+    "prettier": "^3.7.4",
     "sharp": "^0.34.3"
   },
   "dependencies": {
+    "@codemirror/autocomplete": "^6.20.1",
+    "@codemirror/commands": "^6.10.2",
+    "@codemirror/lang-css": "^6.3.1",
+    "@codemirror/lang-html": "^6.4.11",
+    "@codemirror/lang-javascript": "^6.2.5",
+    "@codemirror/lang-json": "^6.0.2",
+    "@codemirror/lang-markdown": "^6.5.0",
+    "@codemirror/lang-python": "^6.2.1",
+    "@codemirror/language": "^6.12.2",
+    "@codemirror/lint": "^6.9.5",
+    "@codemirror/search": "^6.6.0",
+    "@codemirror/state": "^6.5.4",
+    "@codemirror/theme-one-dark": "^6.1.3",
+    "@codemirror/view": "^6.39.16",
     "codemirror": "^6.0.2",
-    "convertapi": "^1.15.0",
+    "core-util-is": "^1.0.3",
-    "dompurify": "^3.2.6",
+    "docx": "^9.6.0",
+    "docx4js": "^2.0.1",
+    "dompurify": "^3.3.1",
     "electron-store": "^10.1.0",
+    "ffmpeg-static": "^5.3.0",
     "highlight.js": "^11.11.1",
-    "marked": "^16.2.1",
+    "html2pdf.js": "^0.14.0",
-    "tslib": "^2.8.1",
+    "marked": "^17.0.3",
-    "xlsx": "^0.18.5"
+    "marked-footnote": "^1.4.0",
+    "marked-highlight": "^2.2.3",
+    "mermaid": "^11.12.3",
+    "pdf-lib": "^1.17.1",
+    "pdfjs-dist": "^5.5.207",
+    "pdfkit": "^0.17.2",
+    "pizzip": "^3.2.0",
+    "simple-git": "^3.32.3",
+    "tslib": "^2.8.1"
+  },
+  "overrides": {
+    "jszip": "^3.10.1",
+    "nth-check": "^2.1.1",
+    "lodash.pick": "npm:lodash@^4.17.21",
+    "lodash-es": "^4.18.1",
+    "lodash": "^4.17.21"
   },
   "build": {
-    "appId": "com.panconverter.app",
+    "appId": "com.concreteinfo.markdownconverter",
-    "productName": "PanConverter",
+    "productName": "MarkdownConverter",
+    "copyright": "Copyright (C) 2024-2025 ConcreteInfo",
     "directories": {
       "output": "dist"
     },
@@ -53,6 +112,10 @@
       "node_modules/**/*",
       "package.json"
     ],
+    "asarUnpack": [
+      "node_modules/ffmpeg-static/**"
+    ],
+    "extraFiles": [],
     "fileAssociations": [
       {
         "ext": "md",
@@ -67,10 +130,18 @@
         "description": "Markdown Document",
         "mimeType": "text/markdown",
         "role": "Editor"
+      },
+      {
+        "ext": "pdf",
+        "name": "PDF Document",
+        "description": "PDF Document",
+        "mimeType": "application/pdf",
+        "role": "Editor"
       }
     ],
     "mac": {
-      "category": "public.app-category.productivity"
+      "category": "public.app-category.productivity",
+      "identity": null
     },
     "win": {
       "target": [
@@ -95,7 +166,15 @@
       ],
       "artifactName": "${productName}-${version}-${arch}.${ext}",
       "requestedExecutionLevel": "asInvoker",
-      "signAndEditExecutable": false
+      "legalTrademarks": "Copyright (C) 2024-2025 ConcreteInfo",
+      "verifyUpdateCodeSignature": false,
+      "signAndEditExecutable": false,
+      "extraFiles": [
+        {
+          "from": "bin/win32/pandoc.exe",
+          "to": "bin/pandoc.exe"
+        }
+      ]
     },
     "nsis": {
       "oneClick": false,
@@ -104,7 +183,7 @@
       "displayLanguageSelector": true,
       "createDesktopShortcut": true,
       "createStartMenuShortcut": true,
-      "shortcutName": "PanConverter",
+      "shortcutName": "MarkdownConverter",
       "runAfterFinish": true,
       "menuCategory": "Productivity",
       "license": "LICENSE",
@@ -119,14 +198,22 @@
         "AppImage",
         "snap"
       ],
-      "category": "Utility"
+      "category": "Utility",
+      "maintainer": "ConcreteInfo <amit.wh@gmail.com>",
+      "extraFiles": [
+        {
+          "from": "bin/linux/pandoc",
+          "to": "bin/pandoc"
+        }
+      ]
     },
     "deb": {
       "depends": [
-        "pandoc"
+        "imagemagick",
+        "libreoffice-common"
       ],
-      "description": "Markdown editor and converter using Pandoc",
+      "description": "Professional Markdown editor and universal file converter",
-      "maintainer": "Amit Haridas <amit.wh@gmail.com>"
+      "maintainer": "ConcreteInfo <amit.wh@gmail.com>"
     }
   }
 }

scripts/create-selfsigned-cert.ps1

@@ -0,0 +1,59 @@
+# create-selfsigned-cert.ps1
+# Generates a self-signed code-signing certificate for local/development builds.
+#
+# Usage:
+#   powershell -ExecutionPolicy Bypass -File scripts/create-selfsigned-cert.ps1
+#   npm run create-cert
+#
+# Then build with:
+#   $env:CSC_LINK="code-signing-cert.pfx"; $env:CSC_KEY_PASSWORD="YourPassword"; npm run build:win-signed
+#
+# NOTE: Self-signed certificates will still show a SmartScreen warning for end users.
+# For production releases, obtain an OV or EV certificate from a trusted CA
+# (DigiCert, Sectigo, Certum, etc.). EV certificates bypass SmartScreen immediately.
+# Open-source projects can apply for free signing at https://signpath.io/
+
+param(
+    [string]$CertPassword = "MarkdownConverter2025",
+    [string]$OutputFile   = "code-signing-cert.pfx",
+    [string]$Subject      = "CN=ConcreteInfo, O=ConcreteInfo, L=India, C=IN"
+)
+
+Write-Host "Creating self-signed code-signing certificate..." -ForegroundColor Cyan
+
+# Create the certificate in the current user's certificate store
+$cert = New-SelfSignedCertificate `
+    -Type CodeSigningCert `
+    -Subject $Subject `
+    -CertStoreLocation "Cert:\CurrentUser\My" `
+    -NotAfter (Get-Date).AddYears(3) `
+    -HashAlgorithm SHA256 `
+    -KeyLength 4096 `
+    -KeyUsage DigitalSignature
+
+if (-not $cert) {
+    Write-Error "Failed to create certificate."
+    exit 1
+}
+
+Write-Host "Certificate created: $($cert.Thumbprint)" -ForegroundColor Green
+
+# Export to PFX
+$securePassword = ConvertTo-SecureString -String $CertPassword -Force -AsPlainText
+$exportPath = Join-Path (Get-Location) $OutputFile
+
+Export-PfxCertificate -Cert $cert -FilePath $exportPath -Password $securePassword | Out-Null
+
+if (Test-Path $exportPath) {
+    Write-Host "Certificate exported to: $exportPath" -ForegroundColor Green
+    Write-Host ""
+    Write-Host "To build a signed release:" -ForegroundColor Yellow
+    Write-Host '  $env:CSC_LINK="code-signing-cert.pfx"' -ForegroundColor White
+    Write-Host "  `$env:CSC_KEY_PASSWORD=`"$CertPassword`"" -ForegroundColor White
+    Write-Host "  npm run build:win-signed" -ForegroundColor White
+    Write-Host ""
+    Write-Host "IMPORTANT: Add code-signing-cert.pfx to .gitignore!" -ForegroundColor Red
+} else {
+    Write-Error "Export failed."
+    exit 1
+}

scripts/download-tools.js

@@ -0,0 +1,148 @@
+#!/usr/bin/env node
+/**
+ * Downloads pandoc binary for the current build platform.
+ * Run automatically via `npm run download-tools` before building.
+ * Skips download if binary already exists (idempotent).
+ */
+
+const https = require('https');
+const http = require('http');
+const fs = require('fs');
+const path = require('path');
+const os = require('os');
+const { execSync } = require('child_process');
+
+const PANDOC_VERSION = '3.9.0.2';
+
+const PANDOC_CONFIG = {
+  linux: {
+    url: `https://github.com/jgm/pandoc/releases/download/${PANDOC_VERSION}/pandoc-${PANDOC_VERSION}-linux-amd64.tar.gz`,
+    archiveExt: '.tar.gz',
+    destFile: 'pandoc',
+    extract(archivePath, destDir) {
+      const tmpDir = path.join(os.tmpdir(), `pandoc-${Date.now()}`);
+      fs.mkdirSync(tmpDir, { recursive: true });
+      execSync(`tar -xzf "${archivePath}" -C "${tmpDir}" pandoc-${PANDOC_VERSION}/bin/pandoc`);
+      const src = path.join(tmpDir, `pandoc-${PANDOC_VERSION}`, 'bin', 'pandoc');
+      fs.copyFileSync(src, path.join(destDir, 'pandoc'));
+      fs.chmodSync(path.join(destDir, 'pandoc'), 0o755);
+      fs.rmSync(tmpDir, { recursive: true, force: true });
+    },
+  },
+  win32: {
+    url: `https://github.com/jgm/pandoc/releases/download/${PANDOC_VERSION}/pandoc-${PANDOC_VERSION}-windows-x86_64.zip`,
+    archiveExt: '.zip',
+    destFile: 'pandoc.exe',
+    extract(archivePath, destDir) {
+      const tmpDir = path.join(os.tmpdir(), `pandoc-${Date.now()}`);
+      fs.mkdirSync(tmpDir, { recursive: true });
+      execSync(
+        `powershell -Command "Expand-Archive -Force '${archivePath}' '${tmpDir}'"`,
+      );
+      const src = path.join(tmpDir, `pandoc-${PANDOC_VERSION}`, 'pandoc.exe');
+      fs.copyFileSync(src, path.join(destDir, 'pandoc.exe'));
+      fs.rmSync(tmpDir, { recursive: true, force: true });
+    },
+  },
+  darwin: {
+    url: `https://github.com/jgm/pandoc/releases/download/${PANDOC_VERSION}/pandoc-${PANDOC_VERSION}-x86_64-macOS.zip`,
+    archiveExt: '.zip',
+    destFile: 'pandoc',
+    extract(archivePath, destDir) {
+      const tmpDir = path.join(os.tmpdir(), `pandoc-${Date.now()}`);
+      fs.mkdirSync(tmpDir, { recursive: true });
+      execSync(`unzip -o "${archivePath}" -d "${tmpDir}"`);
+      const src = path.join(tmpDir, `pandoc-${PANDOC_VERSION}`, 'bin', 'pandoc');
+      fs.copyFileSync(src, path.join(destDir, 'pandoc'));
+      fs.chmodSync(path.join(destDir, 'pandoc'), 0o755);
+      fs.rmSync(tmpDir, { recursive: true, force: true });
+    },
+  },
+};
+
+function download(url, destPath) {
+  return new Promise((resolve, reject) => {
+    const file = fs.createWriteStream(destPath);
+    let received = 0;
+    let total = 0;
+    let lastPct = -1;
+
+    function get(redirectUrl) {
+      const client = redirectUrl.startsWith('https://') ? https : http;
+      client
+        .get(redirectUrl, (res) => {
+          if (res.statusCode === 301 || res.statusCode === 302) {
+            get(res.headers.location);
+            return;
+          }
+          if (res.statusCode !== 200) {
+            reject(new Error(`HTTP ${res.statusCode} for ${redirectUrl}`));
+            return;
+          }
+          total = parseInt(res.headers['content-length'] || '0', 10);
+          res.on('data', (chunk) => {
+            received += chunk.length;
+            if (total > 0) {
+              const pct = Math.floor((received / total) * 100);
+              if (pct !== lastPct && pct % 10 === 0) {
+                process.stdout.write(`  ${pct}%\r`);
+                lastPct = pct;
+              }
+            }
+          });
+          res.pipe(file);
+          file.on('finish', () => {
+            file.close();
+            process.stdout.write('  100%\n');
+            resolve();
+          });
+        })
+        .on('error', (err) => {
+          fs.unlink(destPath, () => {});
+          reject(err);
+        });
+    }
+    get(url);
+  });
+}
+
+async function downloadPandoc() {
+  const platform = process.platform;
+  const config = PANDOC_CONFIG[platform];
+
+  if (!config) {
+    console.log(`[download-tools] No pandoc config for platform "${platform}" — skipping.`);
+    return;
+  }
+
+  const destDir = path.join(__dirname, '..', 'bin', platform);
+  const destFile = path.join(destDir, config.destFile);
+
+  if (fs.existsSync(destFile)) {
+    console.log(`[download-tools] pandoc already present at ${destFile} — skipping.`);
+    return;
+  }
+
+  fs.mkdirSync(destDir, { recursive: true });
+
+  const tmpArchive = path.join(os.tmpdir(), `pandoc-download${config.archiveExt}`);
+
+  console.log(`[download-tools] Downloading pandoc ${PANDOC_VERSION} for ${platform}...`);
+  await download(config.url, tmpArchive);
+
+  console.log(`[download-tools] Extracting to ${destDir}...`);
+  config.extract(tmpArchive, destDir);
+
+  try {
+    fs.unlinkSync(tmpArchive);
+  } catch (_) {
+    /* ignore */
+  }
+
+  console.log(`[download-tools] pandoc ready: ${destFile}`);
+}
+
+downloadPandoc().catch((err) => {
+  console.error('[download-tools] FAILED:', err.message);
+  process.exit(1);
+});

scripts/generate-icons.js

@@ -1,43 +1,82 @@
+/**
+ * Icon Generator for MarkdownConverter
+ * Generates all required icon sizes from NewIcon.jpg
+ */
+
 const sharp = require('sharp');
 const fs = require('fs');
 const path = require('path');
 
-const sizes = {
+// Source image
-    'icon.png': 512,
+const sourceImage = path.join(__dirname, '..', 'assets', 'docico1.png');
-    'icon@2x.png': 1024,
+const assetsDir = path.join(__dirname, '..', 'assets');
-    'icon.ico': 256,
-    'icon.icns': 512
-};
 
-const svgPath = path.join(__dirname, '..', 'assets', 'icon.svg');
+// Icon sizes needed for different platforms
-const svgBuffer = fs.readFileSync(svgPath);
+const iconSizes = [16, 24, 32, 48, 64, 128, 256, 512, 1024];
 
 async function generateIcons() {
-    for (const [filename, size] of Object.entries(sizes)) {
+  console.log('Generating icons from docico1.png...');
-        const outputPath = path.join(__dirname, '..', 'assets', filename);
+
-        
+  // Check if source exists
-        if (filename.endsWith('.png')) {
+  if (!fs.existsSync(sourceImage)) {
-            await sharp(svgBuffer)
+    console.error('Source image not found:', sourceImage);
-                .resize(size, size)
+    process.exit(1);
-                .png()
+  }
-                .toFile(outputPath);
+
-            console.log(`Generated ${filename}`);
+  try {
-        } else if (filename.endsWith('.ico')) {
+    // Generate main icon.png (512x512)
-            // For ICO, we'll just use the PNG version
+    await sharp(sourceImage)
-            await sharp(svgBuffer)
+      .resize(512, 512, { fit: 'contain', background: { r: 255, g: 255, b: 255, alpha: 0 } })
-                .resize(size, size)
+      .png()
-                .png()
+      .toFile(path.join(assetsDir, 'icon.png'));
-                .toFile(outputPath.replace('.ico', '.png'));
+    console.log('Generated icon.png (512x512)');
-            console.log(`Generated ${filename.replace('.ico', '.png')} (use png2ico to convert)`);
+
-        } else if (filename.endsWith('.icns')) {
+    // Generate icon@2x.png (1024x1024)
-            // For ICNS, we'll just use the PNG version
+    await sharp(sourceImage)
-            await sharp(svgBuffer)
+      .resize(1024, 1024, { fit: 'contain', background: { r: 255, g: 255, b: 255, alpha: 0 } })
-                .resize(size, size)
+      .png()
-                .png()
+      .toFile(path.join(assetsDir, 'icon@2x.png'));
-                .toFile(outputPath.replace('.icns', '.png'));
+    console.log('Generated icon@2x.png (1024x1024)');
-            console.log(`Generated ${filename.replace('.icns', '.png')} (use png2icns to convert)`);
+
-        }
+    // Create icons directory for multi-size icons
+    const iconsDir = path.join(assetsDir, 'icons');
+    if (!fs.existsSync(iconsDir)) {
+      fs.mkdirSync(iconsDir, { recursive: true });
     }
+
+    // Generate all sizes
+    for (const size of iconSizes) {
+      await sharp(sourceImage)
+        .resize(size, size, { fit: 'contain', background: { r: 255, g: 255, b: 255, alpha: 0 } })
+        .png()
+        .toFile(path.join(iconsDir, `${size}x${size}.png`));
+      console.log(`Generated icons/${size}x${size}.png`);
+    }
+
+    // Generate favicon
+    await sharp(sourceImage)
+      .resize(32, 32, { fit: 'contain', background: { r: 255, g: 255, b: 255, alpha: 0 } })
+      .png()
+      .toFile(path.join(assetsDir, 'favicon.png'));
+    console.log('Generated favicon.png (32x32)');
+
+    // Generate tray icon (smaller, for system tray)
+    await sharp(sourceImage)
+      .resize(24, 24, { fit: 'contain', background: { r: 255, g: 255, b: 255, alpha: 0 } })
+      .png()
+      .toFile(path.join(assetsDir, 'tray-icon.png'));
+    console.log('Generated tray-icon.png (24x24)');
+
+    console.log('\nIcon generation complete!');
+    console.log('\nFor Windows .ico file, use an online converter or:');
+    console.log('  magick convert assets/icons/*.png assets/icon.ico');
+    console.log('\nFor macOS .icns file, use:');
+    console.log('  iconutil -c icns assets/icon.iconset -o assets/icon.icns');
+
+  } catch (error) {
+    console.error('Error generating icons:', error);
+    process.exit(1);
+  }
 }
 
-generateIcons().catch(console.error);
+generateIcons();

src/adapters/electron/fs.js

@@ -0,0 +1,111 @@
+/**
+ * Electron File System Adapter
+ *
+ * Implements file system operations for Electron using IPC.
+ * This abstracts file operations to enable easier testing and migration.
+ *
+ * @version 4.4.1
+ */
+
+/**
+ * Electron File System Adapter
+ * @type {import('../types').FileSystemAdapter}
+ */
+const electronFsAdapter = {
+    /**
+     * Read file content
+     * @param {string} path - File path
+     * @returns {Promise<string>} File content
+     */
+    async readFile(path) {
+        return await window.electronAPI.file.read(path);
+    },
+
+    /**
+     * Write content to file
+     * @param {string} path - File path
+     * @param {string} content - File content
+     * @returns {Promise<void>}
+     */
+    async writeFile(path, content) {
+        return await window.electronAPI.file.write(path, content);
+    },
+
+    /**
+     * Delete file
+     * @param {string} path - File path
+     * @returns {Promise<void>}
+     */
+    async deleteFile(path) {
+        return await window.electronAPI.file.delete(path);
+    },
+
+    /**
+     * Ensure directory exists
+     * @param {string} path - Directory path
+     * @returns {Promise<void>}
+     */
+    async ensureDir(path) {
+        return await window.electronAPI.file.ensureDir(path);
+    },
+
+    /**
+     * List directory contents
+     * @param {string} path - Directory path
+     * @returns {Promise<Array<import('../types').FileInfo>>}
+     */
+    async listDirectory(path) {
+        const result = await window.electronAPI.invoke('list-directory', path);
+        if (!result?.entries) {
+            return [];
+        }
+
+        return result.entries.map((entry) => ({
+            name: entry.name,
+            isDir: entry.isDirectory,
+            size: entry.size ?? 0,
+            modified: entry.modified ?? 0,
+            path: entry.path
+        }));
+    },
+
+    /**
+     * Check if path exists
+     * @param {string} path - Path to check
+     * @returns {Promise<boolean>}
+     */
+    async exists(path) {
+        return await window.electronAPI.file.exists(path);
+    },
+
+    /**
+     * Check if path is a directory
+     * @param {string} path - Path to check
+     * @returns {Promise<boolean>}
+     */
+    async isDirectory(path) {
+        return await window.electronAPI.file.isDirectory(path);
+    },
+
+    /**
+     * Copy file or directory
+     * @param {string} source - Source path
+     * @param {string} dest - Destination path
+     * @returns {Promise<void>}
+     */
+    async copy(source, dest) {
+        return await window.electronAPI.file.copy(source, dest);
+    },
+
+    /**
+     * Move file or directory
+     * @param {string} source - Source path
+     * @param {string} dest - Destination path
+     * @returns {Promise<void>}
+     */
+    async move(source, dest) {
+        return await window.electronAPI.file.move(source, dest);
+    }
+};
+
+module.exports = { electronFsAdapter };

src/adapters/types.js

@@ -0,0 +1,133 @@
+/**
+ * Platform Adapter Type Definitions
+ *
+ * This module defines the interfaces for platform-specific operations.
+ * Adapters abstract file system, conversion, and system operations
+ * to enable easier testing and future platform migration.
+ *
+ * @version 4.4.1
+ */
+
+/**
+ * @typedef {Object} FileInfo
+ * @property {string} name - File or directory name
+ * @property {boolean} isDir - True if directory
+ * @property {number} size - File size in bytes
+ * @property {number} modified - Last modified timestamp (ms since epoch)
+ */
+
+/**
+ * @typedef {Object} WatchEvent
+ * @property {string} type - Event type ('add', 'change', 'unlink', 'addDir', 'unlinkDir')
+ * @property {string} path - Affected file/directory path
+ */
+
+/**
+ * @typedef {Object} ConversionOptions
+ * @property {string} format - Output format (pdf, docx, html, etc.)
+ * @property {string} [pdfEngine] - PDF engine for PDF export (xelatex, pdflatex, etc.)
+ * @property {string} [template] - Word template path for DOCX
+ * @property {string} [geometry] - Page geometry for PDF (e.g., 'margin=1in')
+ * @property {string} [header] - Header content
+ * @property {string} [footer] - Footer content
+ * @property {boolean} [toc] - Include table of contents
+ */
+
+/**
+ * @typedef {Object} ConversionResult
+ * @property {string} input - Input file path
+ * @property {string} output - Output file path
+ * @property {boolean} success - Whether conversion succeeded
+ * @property {string} [error] - Error message if failed
+ */
+
+/**
+ * @typedef {Object} PlatformCapabilities
+ * @property {boolean} hasPandoc - Pandoc is available
+ * @property {boolean} hasFfmpeg - FFmpeg is available
+ * @property {boolean} hasLibreOffice - LibreOffice is available
+ * @property {boolean} hasDirectFs - Direct file system access
+ * @property {boolean} hasSystemNotifications - System notifications available
+ * @property {boolean} hasPdfJs - PDF.js available for PDF viewing
+ */
+
+/**
+ * @typedef {Object} DialogOptions
+ * @property {string} [title] - Dialog title
+ * @property {string} [defaultPath] - Default path
+ * @property {string[]} [filters] - File filters [{ name: 'Markdown', extensions: ['md'] }]
+ * @property {string} [buttonLabel] - Custom button label
+ */
+
+/**
+ * @typedef {Object} SystemInfo
+ * @property {string} platform - Operating system (win32, darwin, linux)
+ * @property {string} homeDir - User home directory
+ * @property {string} documentsDir - Documents directory
+ * @property {string} downloadsDir - Downloads directory
+ * @property {string} tempDir - Temporary directory
+ * @property {string} appVersion - Application version
+ */
+
+/**
+ * @typedef {Object} FileSystemAdapter
+ * @property {(path: string) => Promise<string>} readFile - Read file content
+ * @property {(path: string, content: string) => Promise<void>} writeFile - Write file content
+ * @property {(path: string) => Promise<void>} deleteFile - Delete file
+ * @property {(path: string) => Promise<void>} ensureDir - Ensure directory exists
+ * @property {(path: string) => Promise<FileInfo[]>} listDirectory - List directory contents
+ * @property {(path: string) => Promise<boolean>} exists - Check if path exists
+ * @property {(path: string) => Promise<boolean>} isDirectory - Check if path is directory
+ * @property {(source: string, dest: string) => Promise<void>} copy - Copy file or directory
+ * @property {(source: string, dest: string) => Promise<void>} move - Move file or directory
+ * @property {(path: string, callback: (event: WatchEvent) => void) => () => void>} [watchDirectory] - Watch directory for changes
+ */
+
+/**
+ * @typedef {Object} ConversionAdapter
+ * @property {(input: string, output: string, options: ConversionOptions) => Promise<void>} convertFile - Convert single file
+ * @property {(files: string[], outputDir: string, options: ConversionOptions) => Promise<ConversionResult[]>} batchConvert - Batch convert files
+ * @property {() => Promise<boolean>} checkPandoc - Check if Pandoc is available
+ * @property {() => Promise<boolean>} checkFfmpeg - Check if FFmpeg is available
+ * @property {() => Promise<boolean>} checkLibreOffice - Check if LibreOffice is available
+ */
+
+/**
+ * @typedef {Object} DialogAdapter
+ * @property {(options?: DialogOptions) => Promise<string|null>} showOpenDialog - Show open file dialog
+ * @property {(options?: DialogOptions) => Promise<string[]>} showOpenDialogMulti - Show multi-select open dialog
+ * @property {(options?: DialogOptions) => Promise<string|null>} showSaveDialog - Show save file dialog
+ * @property {(message: string, type?: string) => Promise<void>} showMessage - Show message dialog
+ * @property {(message: string, type?: string) => Promise<boolean>} showConfirm - Show confirmation dialog
+ */
+
+/**
+ * @typedef {Object} SystemAdapter
+ * @property {() => Promise<SystemInfo>} getSystemInfo - Get system information
+ * @property {(title: string, body: string) => Promise<void>} showNotification - Show system notification
+ * @property {(url: string) => Promise<void>} openExternal - Open URL in default browser
+ * @property {(path: string) => Promise<void>} openInExplorer - Open path in file explorer
+ * @property {(path: string) => Promise<void>} openInDefaultApp - Open path in default application
+ */
+
+/**
+ * @typedef {Object} PdfAdapter
+ * @property {(path: string) => Promise<Object>} loadDocument - Load PDF document
+ * @property {(doc: Object, pageNum: number, canvas: HTMLCanvasElement, scale: number, rotation: number) => Promise<void>} renderPage - Render PDF page to canvas
+ * @property {(operations: Object) => Promise<void>} processOperation - Process PDF operation (merge, split, etc.)
+ */
+
+/**
+ * @typedef {Object} PlatformAdapter
+ * @property {string} name - Platform name ('electron', 'web', 'tauri', 'flutter')
+ * @property {FileSystemAdapter} fs - File system operations
+ * @property {ConversionAdapter} convert - Conversion operations
+ * @property {DialogAdapter} dialog - Dialog operations
+ * @property {SystemAdapter} system - System operations
+ * @property {PdfAdapter} [pdf] - PDF operations (optional, not available on all platforms)
+ * @property {PlatformCapabilities} capabilities - Platform capabilities
+ */
+
+module.exports = {
+    // Type definitions are JSDoc only, no runtime exports needed
+};

src/analytics/analytics-panel.js

@@ -0,0 +1,112 @@
+/**
+ * Writing Analytics Panel — modal overlay displaying analytics dashboard
+ */
+
+const { analyze } = require('./writing-analytics');
+
+function showAnalyticsModal(tabManager) {
+    const existing = document.getElementById('analytics-modal');
+    if (existing) existing.remove();
+
+    const content = tabManager.getEditorContent();
+    const metrics = analyze(content);
+
+    const overlay = document.createElement('div');
+    overlay.id = 'analytics-modal';
+    overlay.className = 'analytics-overlay';
+
+    const maxCount = metrics.topWords.length > 0 ? metrics.topWords[0].count : 1;
+
+    overlay.innerHTML = `
+        <div class="analytics-modal">
+            <div class="analytics-header">
+                <h2>Writing Analytics</h2>
+                <button class="analytics-close" title="Close">&times;</button>
+            </div>
+            <div class="analytics-body">
+                <div class="analytics-section">
+                    <h3>Readability</h3>
+                    <div class="analytics-row">
+                        <span class="analytics-label">Flesch Reading Ease</span>
+                        <span class="analytics-value">${metrics.fleschEase}<small>${metrics.readabilityLabel}</small></span>
+                    </div>
+                    <div class="analytics-row">
+                        <span class="analytics-label">Grade Level</span>
+                        <span class="analytics-value">${metrics.fleschGrade}</span>
+                    </div>
+                    <div class="readability-meter">
+                        <div class="readability-fill" style="width: ${Math.max(0, Math.min(100, metrics.fleschEase))}%"></div>
+                    </div>
+                </div>
+
+                <div class="analytics-section">
+                    <h3>Timing</h3>
+                    <div class="analytics-row">
+                        <span class="analytics-label">Reading Time</span>
+                        <span class="analytics-value">~${metrics.readingTime} min</span>
+                    </div>
+                    <div class="analytics-row">
+                        <span class="analytics-label">Speaking Time</span>
+                        <span class="analytics-value">~${metrics.speakingTime} min</span>
+                    </div>
+                </div>
+
+                <div class="analytics-section">
+                    <h3>Structure</h3>
+                    <div class="analytics-row">
+                        <span class="analytics-label">Sentences</span>
+                        <span class="analytics-value">${metrics.sentenceCount} &bull; Paragraphs: ${metrics.paragraphCount}</span>
+                    </div>
+                    <div class="analytics-row">
+                        <span class="analytics-label">Avg Sentence</span>
+                        <span class="analytics-value">${metrics.avgSentenceLength} words</span>
+                    </div>
+                    ${metrics.longestSentenceLength > 0 ? `
+                    <div class="analytics-row analytics-longest">
+                        <span class="analytics-label">Longest (${metrics.longestSentenceLength} words)</span>
+                        <span class="analytics-value analytics-sentence-preview">${escapeHtml(metrics.longestSentence)}</span>
+                    </div>` : ''}
+                </div>
+
+                <div class="analytics-section">
+                    <h3>Vocabulary</h3>
+                    <div class="analytics-row">
+                        <span class="analytics-label">Unique</span>
+                        <span class="analytics-value">${metrics.uniqueWordCount} / ${metrics.wordCount}<small>${metrics.lexicalDiversity}%</small></span>
+                    </div>
+                    ${metrics.topWords.length > 0 ? `
+                    <div class="word-cloud">
+                        ${metrics.topWords.map(w => {
+                            const scale = 13 + Math.round((w.count / maxCount) * 3);
+                            return `<span class="word-tag" style="font-size:${scale}px">${escapeHtml(w.word)}<small>${w.count}</small></span>`;
+                        }).join('')}
+                    </div>` : ''}
+                </div>
+            </div>
+        </div>
+    `;
+
+    const closeBtn = overlay.querySelector('.analytics-close');
+    closeBtn.addEventListener('click', () => overlay.remove());
+    overlay.addEventListener('click', (e) => {
+        if (e.target === overlay) overlay.remove();
+    });
+
+    const escHandler = (e) => {
+        if (e.key === 'Escape') {
+            overlay.remove();
+            document.removeEventListener('keydown', escHandler);
+        }
+    };
+    document.addEventListener('keydown', escHandler);
+
+    document.body.appendChild(overlay);
+}
+
+function escapeHtml(str) {
+    const div = document.createElement('div');
+    div.textContent = str;
+    return div.innerHTML;
+}
+
+module.exports = { showAnalyticsModal };

src/analytics/writing-analytics.js

@@ -0,0 +1,127 @@
+/**
+ * Writing Analytics — pure computation engine
+ * No DOM dependencies. Exported analyze(text) returns a metrics object.
+ */
+
+const STOP_WORDS = new Set([
+    'the', 'a', 'an', 'is', 'are', 'was', 'were', 'be', 'been',
+    'have', 'has', 'had', 'do', 'does', 'did', 'will', 'would',
+    'could', 'should', 'to', 'of', 'in', 'for', 'on', 'with',
+    'at', 'by', 'from', 'as', 'and', 'or', 'but', 'if', 'it',
+    'its', 'this', 'that', 'these', 'those', 'i', 'me', 'my',
+    'we', 'our', 'you', 'your', 'he', 'him', 'his', 'she', 'her',
+    'they', 'them', 'their', 'not', 'no', 'so', 'than', 'too',
+    'very', 'also', 'just', 'about', 'up', 'out', 'what', 'which', 'who'
+]);
+
+function countSyllables(word) {
+    word = word.toLowerCase().replace(/(?:[^laeiouy]es|ed|[^laeiouy]e)$/, '');
+    word = word.replace(/^y/, '');
+    return word.match(/[aeiouy]{1,2}/gi)?.length || 1;
+}
+
+function extractWords(text) {
+    return text.match(/[a-zA-Z]+(?:['-][a-zA-Z]+)*/g) || [];
+}
+
+function getReadabilityLabel(score) {
+    if (score >= 90) return 'Very Easy';
+    if (score >= 70) return 'Easy';
+    if (score >= 50) return 'Standard';
+    if (score >= 30) return 'Difficult';
+    return 'Very Difficult';
+}
+
+function analyze(text) {
+    if (!text || !text.trim()) {
+        return {
+            wordCount: 0,
+            sentenceCount: 0,
+            paragraphCount: 0,
+            fleschEase: 0,
+            fleschGrade: 0,
+            readabilityLabel: 'N/A',
+            readingTime: 0,
+            speakingTime: 0,
+            uniqueWordCount: 0,
+            lexicalDiversity: 0,
+            avgSentenceLength: 0,
+            longestSentence: '',
+            longestSentenceLength: 0,
+            topWords: []
+        };
+    }
+
+    const words = extractWords(text);
+    const wordCount = words.length;
+
+    const sentences = text.split(/[.!?]+/).map(s => s.trim()).filter(Boolean);
+    const sentenceCount = Math.max(sentences.length, 1);
+
+    const paragraphs = text.split(/\n\s*\n/).map(p => p.trim()).filter(Boolean);
+    const paragraphCount = Math.max(paragraphs.length, 1);
+
+    let totalSyllables = 0;
+    for (const w of words) {
+        totalSyllables += countSyllables(w);
+    }
+
+    const fleschEase = Math.round((206.835 - 1.015 * (wordCount / sentenceCount) - 84.6 * (totalSyllables / wordCount)) * 10) / 10;
+    const fleschGrade = Math.round((0.39 * (wordCount / sentenceCount) + 11.8 * (totalSyllables / wordCount) - 15.59) * 10) / 10;
+    const readabilityLabel = getReadabilityLabel(fleschEase);
+
+    const readingTime = Math.ceil(wordCount / 200);
+    const speakingTime = Math.ceil(wordCount / 130);
+
+    const uniqueWords = new Set(words.map(w => w.toLowerCase()));
+    const uniqueWordCount = uniqueWords.size;
+    const lexicalDiversity = wordCount > 0 ? Math.round((uniqueWordCount / wordCount) * 1000) / 10 : 0;
+
+    const avgSentenceLength = Math.round((wordCount / sentenceCount) * 10) / 10;
+
+    let longestSentence = '';
+    let longestSentenceLength = 0;
+    for (const s of sentences) {
+        const sWords = extractWords(s);
+        if (sWords.length > longestSentenceLength) {
+            longestSentenceLength = sWords.length;
+            longestSentence = s.trim();
+        }
+    }
+
+    if (longestSentence.length > 80) {
+        longestSentence = longestSentence.substring(0, 80) + '...';
+    }
+
+    const wordFreq = {};
+    for (const w of words) {
+        const lower = w.toLowerCase();
+        if (!STOP_WORDS.has(lower) && lower.length > 1) {
+            wordFreq[lower] = (wordFreq[lower] || 0) + 1;
+        }
+    }
+
+    const topWords = Object.entries(wordFreq)
+        .sort((a, b) => b[1] - a[1])
+        .slice(0, 10)
+        .map(([word, count]) => ({ word, count }));
+
+    return {
+        wordCount,
+        sentenceCount,
+        paragraphCount,
+        fleschEase,
+        fleschGrade,
+        readabilityLabel,
+        readingTime,
+        speakingTime,
+        uniqueWordCount,
+        lexicalDiversity,
+        avgSentenceLength,
+        longestSentence,
+        longestSentenceLength,
+        topWords
+    };
+}
+
+module.exports = { analyze };

src/ascii-generator.html

@@ -0,0 +1,601 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>ASCII Art Generator - MarkdownConverter</title>
+    <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap" rel="stylesheet">
+    <style>
+        :root {
+            --ci-dark-gray: #464646;
+            --ci-medium-gray: #9a9696;
+            --ci-accent: #e5461f;
+            --ci-light-gray: #e3e3e3;
+            --ci-black: #0d0b09;
+            --ci-white: #ffffff;
+            --ci-bg: #f5f5f5;
+        }
+
+        * {
+            margin: 0;
+            padding: 0;
+            box-sizing: border-box;
+        }
+
+        body {
+            font-family: 'Inter', system-ui, sans-serif;
+            background: var(--ci-bg);
+            color: var(--ci-dark-gray);
+            min-height: 100vh;
+        }
+
+        .header {
+            background: linear-gradient(135deg, var(--ci-dark-gray) 0%, var(--ci-black) 100%);
+            padding: 16px 24px;
+            border-bottom: 3px solid var(--ci-accent);
+            display: flex;
+            align-items: center;
+            justify-content: space-between;
+        }
+
+        .header h1 {
+            color: var(--ci-white);
+            font-size: 1.25rem;
+            font-weight: 600;
+        }
+
+        .container {
+            padding: 24px;
+            max-width: 100%;
+        }
+
+        .section {
+            background: var(--ci-white);
+            border-radius: 12px;
+            padding: 20px;
+            margin-bottom: 20px;
+            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
+        }
+
+        .section-title {
+            font-weight: 600;
+            margin-bottom: 16px;
+            color: var(--ci-dark-gray);
+            font-size: 0.95rem;
+        }
+
+        .mode-tabs {
+            display: flex;
+            gap: 8px;
+            margin-bottom: 20px;
+        }
+
+        .mode-tab {
+            padding: 10px 20px;
+            border: 2px solid var(--ci-light-gray);
+            background: var(--ci-white);
+            border-radius: 8px;
+            font-size: 0.875rem;
+            font-weight: 500;
+            cursor: pointer;
+            transition: all 0.2s;
+        }
+
+        .mode-tab:hover {
+            border-color: var(--ci-accent);
+        }
+
+        .mode-tab.active {
+            background: var(--ci-accent);
+            border-color: var(--ci-accent);
+            color: var(--ci-white);
+        }
+
+        .form-group {
+            margin-bottom: 16px;
+        }
+
+        .form-label {
+            display: block;
+            font-size: 0.875rem;
+            font-weight: 500;
+            margin-bottom: 8px;
+            color: var(--ci-dark-gray);
+        }
+
+        .form-input, .form-select, .form-textarea {
+            width: 100%;
+            padding: 10px 14px;
+            border: 2px solid var(--ci-light-gray);
+            border-radius: 8px;
+            font-size: 0.875rem;
+            font-family: inherit;
+            transition: border-color 0.2s;
+        }
+
+        .form-input:focus, .form-select:focus, .form-textarea:focus {
+            outline: none;
+            border-color: var(--ci-accent);
+        }
+
+        .form-textarea {
+            min-height: 80px;
+            resize: vertical;
+        }
+
+        .preview-container {
+            background: var(--ci-black);
+            border-radius: 8px;
+            padding: 16px;
+            min-height: 200px;
+            max-height: 350px;
+            overflow: auto;
+        }
+
+        .preview-content {
+            font-family: 'JetBrains Mono', monospace;
+            font-size: 12px;
+            line-height: 1.3;
+            color: #00ff00;
+            white-space: pre;
+        }
+
+        .template-grid {
+            display: grid;
+            grid-template-columns: repeat(4, 1fr);
+            gap: 8px;
+            margin-bottom: 16px;
+        }
+
+        .template-btn {
+            padding: 8px 12px;
+            border: 2px solid var(--ci-light-gray);
+            background: var(--ci-white);
+            border-radius: 6px;
+            font-size: 0.75rem;
+            cursor: pointer;
+            transition: all 0.2s;
+        }
+
+        .template-btn:hover {
+            border-color: var(--ci-accent);
+            background: rgba(229, 70, 31, 0.05);
+        }
+
+        .template-btn.active {
+            border-color: var(--ci-accent);
+            background: rgba(229, 70, 31, 0.1);
+        }
+
+        .footer {
+            display: flex;
+            justify-content: flex-end;
+            gap: 12px;
+            padding: 16px 24px;
+            background: var(--ci-white);
+            border-top: 1px solid var(--ci-light-gray);
+            position: sticky;
+            bottom: 0;
+        }
+
+        .btn {
+            padding: 10px 24px;
+            border-radius: 8px;
+            font-size: 0.875rem;
+            font-weight: 500;
+            cursor: pointer;
+            transition: all 0.2s;
+            border: none;
+        }
+
+        .btn-primary {
+            background: var(--ci-accent);
+            color: var(--ci-white);
+        }
+
+        .btn-primary:hover {
+            background: #c93a18;
+            transform: translateY(-1px);
+        }
+
+        .btn-secondary {
+            background: var(--ci-light-gray);
+            color: var(--ci-dark-gray);
+        }
+
+        .btn-secondary:hover {
+            background: #d0d0d0;
+        }
+
+        .mode-section {
+            display: none;
+        }
+
+        .mode-section.active {
+            display: block;
+        }
+
+        .template-category {
+            margin-bottom: 16px;
+        }
+
+        .template-category-title {
+            font-size: 0.8rem;
+            color: var(--ci-medium-gray);
+            margin-bottom: 8px;
+            text-transform: uppercase;
+            letter-spacing: 0.05em;
+        }
+    </style>
+</head>
+<body>
+    <div class="header">
+        <h1>ASCII Art Generator</h1>
+    </div>
+
+    <div class="container">
+        <div class="section">
+            <div class="mode-tabs">
+                <button class="mode-tab active" data-mode="text">Text Banner</button>
+                <button class="mode-tab" data-mode="box">Box/Frame</button>
+                <button class="mode-tab" data-mode="templates">Templates</button>
+            </div>
+
+            <!-- Text Banner Mode -->
+            <div id="text-mode" class="mode-section active">
+                <div class="form-group">
+                    <label class="form-label">Text to Convert</label>
+                    <input type="text" id="text-input" class="form-input" placeholder="Enter your text..." maxlength="30">
+                </div>
+                <div class="form-group">
+                    <label class="form-label">Style</label>
+                    <select id="font-style" class="form-select">
+                        <option value="standard">Standard</option>
+                        <option value="banner">Banner</option>
+                        <option value="block">Block</option>
+                        <option value="bubble">Bubble</option>
+                        <option value="digital">Digital</option>
+                    </select>
+                </div>
+            </div>
+
+            <!-- Box/Frame Mode -->
+            <div id="box-mode" class="mode-section">
+                <div class="form-group">
+                    <label class="form-label">Text Content</label>
+                    <textarea id="box-text" class="form-textarea" placeholder="Enter text for the box..."></textarea>
+                </div>
+                <div class="form-group">
+                    <label class="form-label">Box Style</label>
+                    <select id="box-style" class="form-select">
+                        <option value="single">Single Line</option>
+                        <option value="double">Double Line</option>
+                        <option value="rounded">Rounded</option>
+                        <option value="bold">Bold</option>
+                        <option value="ascii">ASCII (+|-)</option>
+                    </select>
+                </div>
+                <div class="form-group">
+                    <label class="form-label">Padding</label>
+                    <input type="number" id="box-padding" class="form-input" min="0" max="10" value="2" style="width: 100px;">
+                </div>
+            </div>
+
+            <!-- Templates Mode -->
+            <div id="templates-mode" class="mode-section">
+                <div class="template-category">
+                    <div class="template-category-title">Arrows & Flow</div>
+                    <div class="template-grid">
+                        <button class="template-btn" data-template="arrow-right">Arrow Right</button>
+                        <button class="template-btn" data-template="arrow-down">Arrow Down</button>
+                        <button class="template-btn" data-template="decision">Decision</button>
+                        <button class="template-btn" data-template="process">Process Flow</button>
+                    </div>
+                </div>
+                <div class="template-category">
+                    <div class="template-category-title">Diagrams</div>
+                    <div class="template-grid">
+                        <button class="template-btn" data-template="flowchart">Flowchart</button>
+                        <button class="template-btn" data-template="sequence">Sequence</button>
+                        <button class="template-btn" data-template="network">Network</button>
+                        <button class="template-btn" data-template="hierarchy">Hierarchy</button>
+                    </div>
+                </div>
+                <div class="template-category">
+                    <div class="template-category-title">Boxes & Containers</div>
+                    <div class="template-grid">
+                        <button class="template-btn" data-template="header">Header</button>
+                        <button class="template-btn" data-template="note">Note Box</button>
+                        <button class="template-btn" data-template="warning">Warning</button>
+                        <button class="template-btn" data-template="info">Info Box</button>
+                    </div>
+                </div>
+                <div class="template-category">
+                    <div class="template-category-title">Decorative</div>
+                    <div class="template-grid">
+                        <button class="template-btn" data-template="divider">Divider</button>
+                        <button class="template-btn" data-template="separator">Separator</button>
+                        <button class="template-btn" data-template="banner">Banner</button>
+                        <button class="template-btn" data-template="checklist">Checklist</button>
+                    </div>
+                </div>
+            </div>
+        </div>
+
+        <div class="section">
+            <div class="section-title">Preview</div>
+            <div class="preview-container">
+                <div id="preview" class="preview-content"></div>
+            </div>
+        </div>
+    </div>
+
+    <div class="footer">
+        <button class="btn btn-secondary" id="btn-generate">Generate Preview</button>
+        <button class="btn btn-primary" id="btn-insert">Insert to Editor</button>
+    </div>
+
+    <script>
+        // ASCII Art Generator Logic
+        const FONTS = {
+            standard: {
+                height: 5,
+                chars: {
+                    'A': ['  /\\  ', ' /  \\ ', '/----\\', '|    |', '|    |'],
+                    'B': ['|----\\', '|    |', '|----/', '|    \\', '|----/'],
+                    'C': ['/----\\', '|     ', '|     ', '|     ', '\\----/'],
+                    'D': ['|----\\', '|    |', '|    |', '|    |', '|----/'],
+                    'E': ['|----', '|    ', '|--- ', '|    ', '|----'],
+                    'F': ['|----', '|    ', '|--- ', '|    ', '|    '],
+                    'G': ['/----\\', '|     ', '| |--\\', '|    |', '\\----/'],
+                    'H': ['|    |', '|    |', '|----/', '|    |', '|    |'],
+                    'I': ['|---|', '  |  ', '  |  ', '  |  ', '|---|'],
+                    'J': ['    |', '    |', '    |', '|   |', '\\---/'],
+                    'K': ['|   /', '|  / ', '|--  ', '|  \\ ', '|   \\'],
+                    'L': ['|    ', '|    ', '|    ', '|    ', '|----'],
+                    'M': ['|\\  /|', '| \\/ |', '|    |', '|    |', '|    |'],
+                    'N': ['|\\   |', '| \\  |', '|  \\ |', '|   \\|', '|    |'],
+                    'O': ['/----\\', '|    |', '|    |', '|    |', '\\----/'],
+                    'P': ['|----\\', '|    |', '|----/', '|     ', '|     '],
+                    'Q': ['/----\\', '|    |', '|  \\ |', '|   \\|', '\\----\\'],
+                    'R': ['|----\\', '|    |', '|----/', '|  \\  ', '|   \\ '],
+                    'S': ['/----\\', '|     ', '\\----\\', '     |', '\\----/'],
+                    'T': ['-----', '  |  ', '  |  ', '  |  ', '  |  '],
+                    'U': ['|    |', '|    |', '|    |', '|    |', '\\----/'],
+                    'V': ['|    |', '|    |', ' \\  / ', '  \\/  ', '      '],
+                    'W': ['|    |', '|    |', '|    |', '| /\\ |', '|/  \\|'],
+                    'X': ['\\    /', ' \\  / ', '  \\/  ', '  /\\  ', ' /  \\ '],
+                    'Y': ['\\   /', ' \\ / ', '  |  ', '  |  ', '  |  '],
+                    'Z': ['-----', '   / ', '  /  ', ' /   ', '-----'],
+                    ' ': ['     ', '     ', '     ', '     ', '     '],
+                    '0': ['/---\\', '|   |', '| / |', '|/  |', '\\---/'],
+                    '1': ['  /| ', ' / | ', '   | ', '   | ', ' ----'],
+                    '2': ['/---\\', '    |', ' ---/', '/    ', '-----'],
+                    '3': ['----\\', '    |', ' ---/', '    |', '----/'],
+                    '4': ['|   |', '|   |', '-----', '    |', '    |'],
+                    '5': ['-----', '|    ', '----\\', '    |', '----/'],
+                    '6': ['/----', '|    ', '|---\\', '|   |', '\\---/'],
+                    '7': ['-----', '   / ', '  /  ', ' /   ', '/    '],
+                    '8': ['/---\\', '|   |', ' --- ', '|   |', '\\---/'],
+                    '9': ['/---\\', '|   |', '\\----', '    |', '----/']
+                }
+            },
+            banner: {
+                height: 7,
+                chars: {
+                    'A': [' ##### ', ' ##   ##', '##     ##', '#########', '##     ##', '##     ##', '##     ##'],
+                    'B': ['######## ', '##     ##', '##     ##', '######## ', '##     ##', '##     ##', '######## '],
+                    'C': [' ###### ', '##    ##', '##      ', '##      ', '##      ', '##    ##', ' ###### '],
+                    'D': ['######## ', '##     ##', '##     ##', '##     ##', '##     ##', '##     ##', '######## '],
+                    'E': ['########', '##      ', '##      ', '###### ', '##      ', '##      ', '########'],
+                    'F': ['########', '##      ', '##      ', '###### ', '##      ', '##      ', '##      '],
+                    'G': [' ###### ', '##    ##', '##      ', '##  ####', '##    ##', '##    ##', ' ###### '],
+                    'H': ['##     ##', '##     ##', '##     ##', '#########', '##     ##', '##     ##', '##     ##'],
+                    'I': ['####', ' ## ', ' ## ', ' ## ', ' ## ', ' ## ', '####'],
+                    'J': ['      ##', '      ##', '      ##', '      ##', '##    ##', '##    ##', ' ###### '],
+                    'K': ['##    ##', '##   ## ', '##  ##  ', '#####   ', '##  ##  ', '##   ## ', '##    ##'],
+                    'L': ['##      ', '##      ', '##      ', '##      ', '##      ', '##      ', '########'],
+                    'M': ['##     ##', '###   ###', '#### ####', '## ### ##', '##     ##', '##     ##', '##     ##'],
+                    'N': ['##    ##', '###   ##', '####  ##', '## ## ##', '##  ####', '##   ###', '##    ##'],
+                    'O': [' ####### ', '##     ##', '##     ##', '##     ##', '##     ##', '##     ##', ' ####### '],
+                    'P': ['######## ', '##     ##', '##     ##', '######## ', '##       ', '##       ', '##       '],
+                    'Q': [' ####### ', '##     ##', '##     ##', '##     ##', '##  ## ##', '##    ## ', ' ##### ##'],
+                    'R': ['######## ', '##     ##', '##     ##', '######## ', '##   ##  ', '##    ## ', '##     ##'],
+                    'S': [' ###### ', '##    ##', '##      ', ' ###### ', '      ##', '##    ##', ' ###### '],
+                    'T': ['########', '   ##   ', '   ##   ', '   ##   ', '   ##   ', '   ##   ', '   ##   '],
+                    'U': ['##     ##', '##     ##', '##     ##', '##     ##', '##     ##', '##     ##', ' ####### '],
+                    'V': ['##     ##', '##     ##', '##     ##', '##     ##', ' ##   ## ', '  ## ##  ', '   ###   '],
+                    'W': ['##      ##', '##  ##  ##', '##  ##  ##', '##  ##  ##', '##  ##  ##', '##  ##  ##', ' ###  ### '],
+                    'X': ['##     ##', ' ##   ## ', '  ## ##  ', '   ###   ', '  ## ##  ', ' ##   ## ', '##     ##'],
+                    'Y': ['##    ##', ' ##  ## ', '  ####  ', '   ##   ', '   ##   ', '   ##   ', '   ##   '],
+                    'Z': ['########', '     ## ', '    ##  ', '   ##   ', '  ##    ', ' ##     ', '########'],
+                    ' ': ['       ', '       ', '       ', '       ', '       ', '       ', '       '],
+                    '0': [' ###### ', '##    ##', '##    ##', '##    ##', '##    ##', '##    ##', ' ###### '],
+                    '1': ['   ##   ', ' ####   ', '   ##   ', '   ##   ', '   ##   ', '   ##   ', ' ###### '],
+                    '2': [' ###### ', '##    ##', '     ## ', '   ##   ', '  ##    ', ' ##     ', '########'],
+                    '3': [' ###### ', '##    ##', '     ## ', '  ####  ', '     ## ', '##    ##', ' ###### '],
+                    '4': ['    ##  ', '   ###  ', '  # ##  ', ' #  ##  ', '########', '    ##  ', '    ##  '],
+                    '5': ['########', '##      ', '####### ', '      ##', '      ##', '##    ##', ' ###### '],
+                    '6': [' ###### ', '##      ', '####### ', '##    ##', '##    ##', '##    ##', ' ###### '],
+                    '7': ['########', '##   ## ', '    ##  ', '   ##   ', '  ##    ', '  ##    ', '  ##    '],
+                    '8': [' ###### ', '##    ##', '##    ##', ' ###### ', '##    ##', '##    ##', ' ###### '],
+                    '9': [' ###### ', '##    ##', '##    ##', ' #######', '      ##', '##    ##', ' ###### ']
+                }
+            },
+            block: {
+                height: 6,
+                chars: {
+                    'A': ['█████╗ ', '██╔══██╗', '███████║', '██╔══██║', '██║  ██║', '╚═╝  ╚═╝'],
+                    'B': ['██████╗ ', '██╔══██╗', '██████╔╝', '██╔══██╗', '██████╔╝', '╚═════╝ '],
+                    'C': ['█████╗ ', '██╔══██╗', '██║     ', '██║     ', '╚█████╔╝', ' ╚════╝ '],
+                    'D': ['██████╗ ', '██╔══██╗', '██║  ██║', '██║  ██║', '██████╔╝', '╚═════╝ '],
+                    'E': ['███████╗', '██╔════╝', '█████╗  ', '██╔══╝  ', '███████╗', '╚══════╝'],
+                    'F': ['███████╗', '██╔════╝', '█████╗  ', '██╔══╝  ', '██║     ', '╚═╝     '],
+                    'G': ['█████╗ ', '██╔══██╗', '██║  ███', '██║   ██', '╚█████╔╝', ' ╚════╝ '],
+                    'H': ['██╗  ██╗', '██║  ██║', '███████║', '██╔══██║', '██║  ██║', '╚═╝  ╚═╝'],
+                    'I': ['██╗', '██║', '██║', '██║', '██║', '╚═╝'],
+                    'J': ['    ██╗', '    ██║', '    ██║', '██  ██║', '╚████╔╝', ' ╚═══╝ '],
+                    'K': ['██╗  ██╗', '██║ ██╔╝', '█████╔╝ ', '██╔═██╗ ', '██║  ██╗', '╚═╝  ╚═╝'],
+                    'L': ['██╗     ', '██║     ', '██║     ', '██║     ', '███████╗', '╚══════╝'],
+                    'M': ['███╗   ███╗', '████╗ ████║', '██╔████╔██║', '██║╚██╔╝██║', '██║ ╚═╝ ██║', '╚═╝     ╚═╝'],
+                    'N': ['███╗   ██╗', '████╗  ██║', '██╔██╗ ██║', '██║╚██╗██║', '██║ ╚████║', '╚═╝  ╚═══╝'],
+                    'O': ['█████╗ ', '██╔══██╗', '██║  ██║', '██║  ██║', '╚█████╔╝', ' ╚════╝ '],
+                    'P': ['██████╗ ', '██╔══██╗', '██████╔╝', '██╔═══╝ ', '██║     ', '╚═╝     '],
+                    'Q': ['█████╗ ', '██╔══██╗', '██║  ██║', '██║  ██║', '╚██████╗', ' ╚═══██╝'],
+                    'R': ['██████╗ ', '██╔══██╗', '██████╔╝', '██╔══██╗', '██║  ██║', '╚═╝  ╚═╝'],
+                    'S': ['█████╗ ', '██╔══╝ ', '█████╗ ', '╚══██║ ', '█████║ ', '╚════╝ '],
+                    'T': ['████████╗', '╚══██╔══╝', '   ██║   ', '   ██║   ', '   ██║   ', '   ╚═╝   '],
+                    'U': ['██╗  ██╗', '██║  ██║', '██║  ██║', '██║  ██║', '╚█████╔╝', ' ╚════╝ '],
+                    'V': ['██╗   ██╗', '██║   ██║', '██║   ██║', '╚██╗ ██╔╝', ' ╚████╔╝ ', '  ╚═══╝  '],
+                    'W': ['██╗    ██╗', '██║    ██║', '██║ █╗ ██║', '██║███╗██║', '╚███╔███╔╝', ' ╚══╝╚══╝ '],
+                    'X': ['██╗  ██╗', '╚██╗██╔╝', ' ╚███╔╝ ', ' ██╔██╗ ', '██╔╝ ██╗', '╚═╝  ╚═╝'],
+                    'Y': ['██╗   ██╗', '╚██╗ ██╔╝', ' ╚████╔╝ ', '  ╚██╔╝  ', '   ██║   ', '   ╚═╝   '],
+                    'Z': ['███████╗', '╚════██║', '  ███╔═╝', ' ██╔══╝ ', '███████╗', '╚══════╝'],
+                    ' ': ['   ', '   ', '   ', '   ', '   ', '   ']
+                }
+            }
+        };
+
+        const TEMPLATES = {
+            'arrow-right': '    ┌─────────────────────┐\n──▶│  Process or Action  │──▶\n    └─────────────────────┘',
+            'arrow-down': '        │\n        ▼\n┌───────────────┐\n│   Process     │\n└───────────────┘\n        │\n        ▼',
+            'decision': '       ╱╲\n      ╱  ╲\n     ╱ ?  ╲\n    ╱      ╲\n   ╱────────╲\n  ╱          ╲\n YES        NO\n  │          │\n  ▼          ▼',
+            'process': '┌─────┐   ┌─────┐   ┌─────┐\n│  1  │──▶│  2  │──▶│  3  │\n└─────┘   └─────┘   └─────┘',
+            'flowchart': '┌─────────────┐\n│   START    │\n└──────┬──────┘\n       │\n       ▼\n┌─────────────┐\n│  Process A  │\n└──────┬──────┘\n       │\n       ▼\n   ╱────────╲\n  ╱ Decision ╲\n  ╲    ?    ╱\n   ╲────────╱\n    │      │\n   YES    NO\n    │      │\n    ▼      ▼\n┌──────┐ ┌──────┐\n│  B   │ │  C   │\n└──────┘ └──────┘',
+            'sequence': ' User      System     Database\n   │           │           │\n   │  Request  │           │\n   ├──────────►│           │\n   │           │  Query    │\n   │           ├──────────►│\n   │           │           │\n   │           │  Result   │\n   │           │◄──────────┤\n   │  Response │           │\n   │◄──────────┤           │\n   │           │           │',
+            'network': '          ┌─────────┐\n          │ Server  │\n          └────┬────┘\n               │\n     ┌─────────┼─────────┐\n     │         │         │\n┌────┴────┐ ┌──┴──┐ ┌────┴────┐\n│ Client1 │ │ DB  │ │ Client2 │\n└─────────┘ └─────┘ └─────────┘',
+            'hierarchy': '            ┌─────────┐\n            │   CEO   │\n            └────┬────┘\n       ┌─────────┼─────────┐\n       │         │         │\n   ┌───┴───┐ ┌───┴───┐ ┌───┴───┐\n   │  VP1  │ │  VP2  │ │  VP3  │\n   └───┬───┘ └───┬───┘ └───┬───┘\n       │         │         │\n   ┌───┴───┐ ┌───┴───┐ ┌───┴───┐\n   │ Team1 │ │ Team2 │ │ Team3 │\n   └───────┘ └───────┘ └───────┘',
+            'header': '╔════════════════════════════════════╗\n║            SECTION TITLE           ║\n╚════════════════════════════════════╝',
+            'note': '┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓\n┃  NOTE:                         ┃\n┃  This is an important note     ┃\n┃  that requires attention!      ┃\n┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛',
+            'warning': '╔════════════════════════════════════╗\n║  ⚠️  WARNING                       ║\n║                                    ║\n║  Critical information here!        ║\n╚════════════════════════════════════╝',
+            'info': '╭────────────────────────────────────╮\n│  ℹ️  INFO                          │\n│                                    │\n│  Helpful information here.         │\n╰────────────────────────────────────╯',
+            'divider': '════════════════════════════════════════',
+            'separator': '╭──────────────────────────────────────╮\n│                                      │\n╰──────────────────────────────────────╯',
+            'banner': '★══════════════════════════════════════★\n║          YOUR TITLE HERE            ║\n★══════════════════════════════════════★',
+            'checklist': '☐ Task 1 - Not completed\n☑ Task 2 - Completed  \n☐ Task 3 - Not completed\n☐ Task 4 - Not completed'
+        };
+
+        const BOX_STYLES = {
+            single: { tl: '┌', tr: '┐', bl: '└', br: '┘', h: '─', v: '│' },
+            double: { tl: '╔', tr: '╗', bl: '╚', br: '╝', h: '═', v: '║' },
+            rounded: { tl: '╭', tr: '╮', bl: '╰', br: '╯', h: '─', v: '│' },
+            bold: { tl: '┏', tr: '┓', bl: '┗', br: '┛', h: '━', v: '┃' },
+            ascii: { tl: '+', tr: '+', bl: '+', br: '+', h: '-', v: '|' }
+        };
+
+        let currentMode = 'text';
+        let currentTemplate = null;
+
+        // Mode switching
+        document.querySelectorAll('.mode-tab').forEach(tab => {
+            tab.addEventListener('click', () => {
+                document.querySelectorAll('.mode-tab').forEach(t => t.classList.remove('active'));
+                tab.classList.add('active');
+                currentMode = tab.dataset.mode;
+
+                document.querySelectorAll('.mode-section').forEach(s => s.classList.remove('active'));
+                document.getElementById(currentMode + '-mode').classList.add('active');
+
+                generatePreview();
+            });
+        });
+
+        // Template selection
+        document.querySelectorAll('.template-btn').forEach(btn => {
+            btn.addEventListener('click', () => {
+                document.querySelectorAll('.template-btn').forEach(b => b.classList.remove('active'));
+                btn.classList.add('active');
+                currentTemplate = btn.dataset.template;
+                generatePreview();
+            });
+        });
+
+        // Generate text banner
+        function generateTextBanner(text, style) {
+            const font = FONTS[style] || FONTS.standard;
+            const lines = Array(font.height).fill('');
+
+            for (const char of text.toUpperCase()) {
+                const charArt = font.chars[char] || font.chars[' '];
+                if (charArt) {
+                    for (let i = 0; i < font.height; i++) {
+                        lines[i] += charArt[i] + ' ';
+                    }
+                }
+            }
+
+            return lines.join('\n');
+        }
+
+        // Generate box
+        function generateBox(text, style, padding) {
+            const box = BOX_STYLES[style] || BOX_STYLES.single;
+            const lines = text.split('\n');
+            const maxLen = Math.max(...lines.map(l => l.length)) + padding * 2;
+
+            let result = box.tl + box.h.repeat(maxLen + 2) + box.tr + '\n';
+
+            // Add padding lines at top
+            for (let i = 0; i < Math.floor(padding / 2); i++) {
+                result += box.v + ' '.repeat(maxLen + 2) + box.v + '\n';
+            }
+
+            // Add text lines
+            for (const line of lines) {
+                const paddedLine = ' '.repeat(padding) + line.padEnd(maxLen - padding) + ' ';
+                result += box.v + ' ' + paddedLine + box.v + '\n';
+            }
+
+            // Add padding lines at bottom
+            for (let i = 0; i < Math.floor(padding / 2); i++) {
+                result += box.v + ' '.repeat(maxLen + 2) + box.v + '\n';
+            }
+
+            result += box.bl + box.h.repeat(maxLen + 2) + box.br;
+            return result;
+        }
+
+        // Generate preview
+        function generatePreview() {
+            let result = '';
+
+            if (currentMode === 'text') {
+                const text = document.getElementById('text-input').value || 'HELLO';
+                const style = document.getElementById('font-style').value;
+                result = generateTextBanner(text, style);
+            } else if (currentMode === 'box') {
+                const text = document.getElementById('box-text').value || 'Your text here';
+                const style = document.getElementById('box-style').value;
+                const padding = parseInt(document.getElementById('box-padding').value) || 2;
+                result = generateBox(text, style, padding);
+            } else if (currentMode === 'templates') {
+                result = currentTemplate ? TEMPLATES[currentTemplate] : 'Select a template...';
+            }
+
+            document.getElementById('preview').textContent = result;
+        }
+
+        // Event listeners for live preview
+        document.getElementById('text-input').addEventListener('input', generatePreview);
+        document.getElementById('font-style').addEventListener('change', generatePreview);
+        document.getElementById('box-text').addEventListener('input', generatePreview);
+        document.getElementById('box-style').addEventListener('change', generatePreview);
+        document.getElementById('box-padding').addEventListener('input', generatePreview);
+
+        document.getElementById('btn-generate').addEventListener('click', generatePreview);
+
+        document.getElementById('btn-insert').addEventListener('click', () => {
+            const content = document.getElementById('preview').textContent;
+            if (content && window.electronAPI) {
+                // Wrap in code block for markdown
+                const wrapped = '```\n' + content + '\n```';
+                window.electronAPI.send('insert-generated-content', wrapped);
+                window.close();
+            }
+        });
+
+        // Initial preview
+        generatePreview();
+    </script>
+</body>
+</html>

src/command-palette.js

@@ -0,0 +1,109 @@
+class CommandPalette {
+    constructor() {
+        this.overlay = document.getElementById('command-palette-overlay');
+        this.input = document.getElementById('command-palette-input');
+        this.results = document.getElementById('command-palette-results');
+        this.commands = [];
+        this.selectedIndex = 0;
+        this.filteredCommands = [];
+        this.setupEventListeners();
+    }
+
+    register(label, shortcut, action) {
+        this.commands.push({ label, shortcut, action });
+    }
+
+    open() {
+        this.overlay.classList.remove('hidden');
+        this.input.value = '';
+        this.input.focus();
+        this.selectedIndex = 0;
+        this.renderResults('');
+    }
+
+    close() {
+        this.overlay.classList.add('hidden');
+    }
+
+    isOpen() {
+        return !this.overlay.classList.contains('hidden');
+    }
+
+    setupEventListeners() {
+        this.input.addEventListener('input', () => {
+            this.selectedIndex = 0;
+            this.renderResults(this.input.value);
+        });
+
+        this.overlay.addEventListener('click', (e) => {
+            if (e.target === this.overlay) this.close();
+        });
+
+        this.input.addEventListener('keydown', (e) => {
+            if (e.key === 'Escape') {
+                e.preventDefault();
+                this.close();
+            } else if (e.key === 'Enter') {
+                e.preventDefault();
+                this.executeSelected();
+            } else if (e.key === 'ArrowDown') {
+                e.preventDefault();
+                this.selectedIndex = Math.min(this.selectedIndex + 1, this.filteredCommands.length - 1);
+                this.updateSelection();
+            } else if (e.key === 'ArrowUp') {
+                e.preventDefault();
+                this.selectedIndex = Math.max(this.selectedIndex - 1, 0);
+                this.updateSelection();
+            }
+        });
+    }
+
+    renderResults(query) {
+        this.filteredCommands = query
+            ? this.commands.filter(cmd => cmd.label.toLowerCase().includes(query.toLowerCase()))
+            : [...this.commands];
+
+        this.results.innerHTML = this.filteredCommands.map((cmd, i) => `
+            <div class="command-item ${i === this.selectedIndex ? 'selected' : ''}" data-index="${i}">
+                <span class="command-label">${this.highlightMatch(cmd.label, query)}</span>
+                ${cmd.shortcut ? `<span class="command-shortcut">${cmd.shortcut}</span>` : ''}
+            </div>
+        `).join('');
+
+        this.results.querySelectorAll('.command-item').forEach((el) => {
+            el.addEventListener('click', () => {
+                const idx = parseInt(el.dataset.index);
+                this.filteredCommands[idx].action();
+                this.close();
+            });
+            el.addEventListener('mouseenter', () => {
+                this.selectedIndex = parseInt(el.dataset.index);
+                this.updateSelection();
+            });
+        });
+    }
+
+    highlightMatch(text, query) {
+        if (!query) return text;
+        const regex = new RegExp(`(${query.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')})`, 'gi');
+        return text.replace(regex, '<strong>$1</strong>');
+    }
+
+    updateSelection() {
+        this.results.querySelectorAll('.command-item').forEach((el, i) => {
+            el.classList.toggle('selected', i === this.selectedIndex);
+        });
+        // Scroll selected into view
+        const selected = this.results.querySelector('.command-item.selected');
+        if (selected) selected.scrollIntoView({ block: 'nearest' });
+    }
+
+    executeSelected() {
+        if (this.filteredCommands[this.selectedIndex]) {
+            this.filteredCommands[this.selectedIndex].action();
+            this.close();
+        }
+    }
+}
+
+module.exports = { CommandPalette };

src/editor/codemirror-setup.js

@@ -0,0 +1,142 @@
+// CodeMirror 6 wrapper module
+// Provides createEditor() and getLanguageExtension() for the rest of the app.
+
+const {
+  EditorView,
+  keymap,
+  lineNumbers,
+  highlightActiveLine,
+  drawSelection,
+} = require('@codemirror/view');
+const { EditorState } = require('@codemirror/state');
+const { markdown, markdownLanguage } = require('@codemirror/lang-markdown');
+// Language extensions loaded lazily on first use
+let _javascript, _html, _css, _json, _python;
+const {
+  defaultKeymap,
+  history,
+  historyKeymap,
+  indentWithTab,
+} = require('@codemirror/commands');
+const {
+  searchKeymap,
+  highlightSelectionMatches,
+} = require('@codemirror/search');
+const {
+  autocompletion,
+  completionKeymap,
+} = require('@codemirror/autocomplete');
+const {
+  bracketMatching,
+  foldGutter,
+  indentOnInput,
+} = require('@codemirror/language');
+const { oneDark } = require('@codemirror/theme-one-dark');
+
+// Custom theme for JetBrains Mono font
+const jetBrainsMonoTheme = EditorView.theme({
+  '&': {
+    fontFamily: "'JetBrains Mono', 'Fira Code', 'SF Mono', Monaco, 'Courier New', monospace"
+  },
+  '.cm-content': {
+    fontFamily: 'inherit'
+  },
+  '.cm-scroller': {
+    fontFamily: 'inherit'
+  }
+});
+
+/**
+ * Create a CodeMirror 6 editor instance.
+ *
+ * @param {HTMLElement} parentElement - DOM element to mount the editor in
+ * @param {Object}  options
+ * @param {string}  options.content          - initial document content (default '')
+ * @param {Function} options.onChange        - called with new content string on every doc change
+ * @param {Function} options.onUpdate       - called with the EditorView on every update (selection, doc change, etc.)
+ * @param {boolean} options.isDark           - apply oneDark theme when true (default false)
+ * @param {boolean} options.showLineNumbers  - show line-number gutter (default true)
+ * @returns {EditorView} the created editor view
+ */
+function createEditor(parentElement, options = {}) {
+  console.log('[createEditor] Called with parentElement:', parentElement?.id, 'dimensions:', parentElement?.clientWidth, 'x', parentElement?.clientHeight);
+  if (!parentElement) {
+    console.error('[createEditor] ERROR: parentElement is null or undefined!');
+    return null;
+  }
+  const {
+    content = '',
+    onChange = () => {},
+    onUpdate = null,
+    isDark = false,
+    showLineNumbers = true,
+  } = options;
+
+  const extensions = [
+    markdown({ base: markdownLanguage }),
+    history(),
+    drawSelection(),
+    highlightActiveLine(),
+    bracketMatching(),
+    indentOnInput(),
+    highlightSelectionMatches(),
+    autocompletion(),
+    foldGutter(),
+    jetBrainsMonoTheme,
+    keymap.of([
+      ...defaultKeymap,
+      ...historyKeymap,
+      ...searchKeymap,
+      ...completionKeymap,
+      indentWithTab,
+    ]),
+    EditorView.updateListener.of((update) => {
+      if (update.docChanged) {
+        onChange(update.state.doc.toString());
+      }
+      if (onUpdate && (update.docChanged || update.selectionSet)) {
+        onUpdate(update.view);
+      }
+    }),
+    EditorView.lineWrapping,
+  ];
+
+  if (showLineNumbers) {
+    extensions.push(lineNumbers());
+  }
+
+  if (isDark) {
+    extensions.push(oneDark);
+  }
+
+  const state = EditorState.create({ doc: content, extensions });
+  const view = new EditorView({ state, parent: parentElement });
+  return view;
+}
+
+/**
+ * Return the appropriate CodeMirror language extension for a given language name.
+ *
+ * Supported values: javascript, js, html, css, json, python, py, markdown.
+ * Falls back to markdown when the language is unrecognised.
+ *
+ * @param {string} lang - language identifier
+ * @returns {Extension} CodeMirror language extension
+ */
+function getLanguageExtension(lang) {
+  const loaders = {
+    javascript: () => { if (!_javascript) _javascript = require('@codemirror/lang-javascript').javascript; return _javascript(); },
+    html: () => { if (!_html) _html = require('@codemirror/lang-html').html; return _html(); },
+    css: () => { if (!_css) _css = require('@codemirror/lang-css').css; return _css(); },
+    json: () => { if (!_json) _json = require('@codemirror/lang-json').json; return _json(); },
+    python: () => { if (!_python) _python = require('@codemirror/lang-python').python; return _python(); },
+    markdown: () => markdown({ base: markdownLanguage }),
+  };
+  loaders.js = loaders.javascript;
+  loaders.py = loaders.python;
+
+  const loader = loaders[lang];
+  return loader ? loader() : markdown({ base: markdownLanguage });
+}
+
+module.exports = { createEditor, getLanguageExtension };

src/fonts.css

@@ -0,0 +1,75 @@
+/* Local Font Definitions for MarkdownConverter */
+
+/* Inter Font Family */
+@font-face {
+    font-family: 'Inter';
+    font-style: normal;
+    font-weight: 300;
+    font-display: swap;
+    src: url('../assets/fonts/Inter-Light.woff2') format('woff2');
+}
+
+@font-face {
+    font-family: 'Inter';
+    font-style: normal;
+    font-weight: 400;
+    font-display: swap;
+    src: url('../assets/fonts/Inter-Regular.woff2') format('woff2');
+}
+
+@font-face {
+    font-family: 'Inter';
+    font-style: normal;
+    font-weight: 500;
+    font-display: swap;
+    src: url('../assets/fonts/Inter-Medium.woff2') format('woff2');
+}
+
+@font-face {
+    font-family: 'Inter';
+    font-style: normal;
+    font-weight: 600;
+    font-display: swap;
+    src: url('../assets/fonts/Inter-SemiBold.woff2') format('woff2');
+}
+
+@font-face {
+    font-family: 'Inter';
+    font-style: normal;
+    font-weight: 700;
+    font-display: swap;
+    src: url('../assets/fonts/Inter-Bold.woff2') format('woff2');
+}
+
+/* JetBrains Mono Font Family - For code, markdown editor, and ASCII art */
+@font-face {
+    font-family: 'JetBrains Mono';
+    font-style: normal;
+    font-weight: 400;
+    font-display: swap;
+    src: url('../assets/fonts/JetBrainsMono-Regular.woff2') format('woff2');
+}
+
+@font-face {
+    font-family: 'JetBrains Mono';
+    font-style: normal;
+    font-weight: 500;
+    font-display: swap;
+    src: url('../assets/fonts/JetBrainsMono-Medium.woff2') format('woff2');
+}
+
+@font-face {
+    font-family: 'JetBrains Mono';
+    font-style: normal;
+    font-weight: 600;
+    font-display: swap;
+    src: url('../assets/fonts/JetBrainsMono-SemiBold.woff2') format('woff2');
+}
+
+@font-face {
+    font-family: 'JetBrains Mono';
+    font-style: normal;
+    font-weight: 700;
+    font-display: swap;
+    src: url('../assets/fonts/JetBrainsMono-Bold.woff2') format('woff2');
+}

src/main/GitOperations.js

@@ -0,0 +1,44 @@
+const simpleGit = require('simple-git');
+
+function getGitInstance(dir) {
+  return simpleGit(dir);
+}
+
+async function getStatus(dir) {
+  try {
+    const git = getGitInstance(dir);
+    return await git.status();
+  } catch (err) {
+    return { error: 'Not a git repository' };
+  }
+}
+
+async function stage(dir, files) {
+  try {
+    const git = getGitInstance(dir);
+    await git.add(files);
+    return await git.status();
+  } catch (err) {
+    return { error: err.message };
+  }
+}
+
+async function commit(dir, message) {
+  try {
+    const git = getGitInstance(dir);
+    return await git.commit(message);
+  } catch (err) {
+    return { error: err.message };
+  }
+}
+
+async function log(dir, maxCount = 20) {
+  try {
+    const git = getGitInstance(dir);
+    return await git.log({ maxCount });
+  } catch (err) {
+    return { error: err.message };
+  }
+}
+
+module.exports = { getStatus, stage, commit, log };

src/main/PDFOperations.js

@@ -0,0 +1,433 @@
+const fs = require('fs');
+const path = require('path');
+const { PDFDocument, rgb, degrees, StandardFonts } = require('pdf-lib');
+
+function parsePageRanges(rangeString, totalPages) {
+  const pages = [];
+  const ranges = rangeString.split(',').map(r => r.trim());
+
+  for (const range of ranges) {
+    if (range.includes('-')) {
+      const [start, end] = range.split('-').map(n => parseInt(n.trim()));
+      for (let i = start; i <= end && i <= totalPages; i++) {
+        if (i > 0 && !pages.includes(i - 1)) {
+          pages.push(i - 1);
+        }
+      }
+    } else {
+      const page = parseInt(range);
+      if (page > 0 && page <= totalPages && !pages.includes(page - 1)) {
+        pages.push(page - 1);
+      }
+    }
+  }
+
+  return pages.sort((a, b) => a - b);
+}
+
+function hexToRgb(hex) {
+  const result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
+  return result ? {
+    r: parseInt(result[1], 16) / 255,
+    g: parseInt(result[2], 16) / 255,
+    b: parseInt(result[3], 16) / 255
+  } : { r: 0, g: 0, b: 0 };
+}
+
+async function pdfMerge(data) {
+  try {
+    const mergedPdf = await PDFDocument.create();
+
+    for (const filePath of data.inputFiles) {
+      const pdfBytes = fs.readFileSync(filePath);
+      const pdf = await PDFDocument.load(pdfBytes);
+      const copiedPages = await mergedPdf.copyPages(pdf, pdf.getPageIndices());
+      copiedPages.forEach(page => mergedPdf.addPage(page));
+    }
+
+    const pdfBytes = await mergedPdf.save();
+    fs.writeFileSync(data.outputPath, pdfBytes);
+
+    return { success: true, message: `Successfully merged ${data.inputFiles.length} PDFs` };
+  } catch (error) {
+    return { success: false, error: error.message };
+  }
+}
+
+async function pdfSplit(data) {
+  try {
+    const pdfBytes = fs.readFileSync(data.inputPath);
+    const pdf = await PDFDocument.load(pdfBytes);
+    const totalPages = pdf.getPageCount();
+
+    const splits = [];
+
+    if (data.splitMode === 'pages') {
+      const ranges = data.pageRanges.split(',').map(r => r.trim());
+      for (let i = 0; i < ranges.length; i++) {
+        const range = ranges[i];
+        const pages = [];
+
+        if (range.includes('-')) {
+          const [start, end] = range.split('-').map(n => parseInt(n.trim()));
+          for (let p = start; p <= end && p <= totalPages; p++) {
+            pages.push(p - 1);
+          }
+        } else {
+          const page = parseInt(range);
+          if (page > 0 && page <= totalPages) {
+            pages.push(page - 1);
+          }
+        }
+
+        if (pages.length > 0) {
+          splits.push({ pages, name: `part_${i + 1}` });
+        }
+      }
+    } else if (data.splitMode === 'interval') {
+      const interval = data.interval;
+      for (let i = 0; i < totalPages; i += interval) {
+        const pages = [];
+        for (let j = i; j < i + interval && j < totalPages; j++) {
+          pages.push(j);
+        }
+        splits.push({ pages, name: `part_${Math.floor(i / interval) + 1}` });
+      }
+    } else if (data.splitMode === 'size') {
+      const chunkSize = Math.max(1, Math.floor(totalPages / 5));
+      for (let i = 0; i < totalPages; i += chunkSize) {
+        const pages = [];
+        for (let j = i; j < i + chunkSize && j < totalPages; j++) {
+          pages.push(j);
+        }
+        splits.push({ pages, name: `part_${Math.floor(i / chunkSize) + 1}` });
+      }
+    }
+
+    const baseName = path.basename(data.inputPath, '.pdf');
+    for (const split of splits) {
+      const newPdf = await PDFDocument.create();
+      const copiedPages = await newPdf.copyPages(pdf, split.pages);
+      copiedPages.forEach(page => newPdf.addPage(page));
+
+      const outputPath = path.join(data.outputFolder, `${baseName}_${split.name}.pdf`);
+      const newPdfBytes = await newPdf.save();
+      fs.writeFileSync(outputPath, newPdfBytes);
+    }
+
+    return { success: true, message: `Successfully split PDF into ${splits.length} files` };
+  } catch (error) {
+    return { success: false, error: error.message };
+  }
+}
+
+async function pdfCompress(data) {
+  try {
+    const pdfBytes = fs.readFileSync(data.inputPath);
+    const pdf = await PDFDocument.load(pdfBytes);
+
+    const compressedPdfBytes = await pdf.save({
+      useObjectStreams: true,
+      addDefaultPage: false,
+      objectsPerTick: 50
+    });
+
+    fs.writeFileSync(data.outputPath, compressedPdfBytes);
+
+    const originalSize = fs.statSync(data.inputPath).size;
+    const compressedSize = fs.statSync(data.outputPath).size;
+    const savings = ((originalSize - compressedSize) / originalSize * 100).toFixed(1);
+
+    return {
+      success: true,
+      message: `PDF compressed. Size reduced by ${savings}% (${(originalSize / 1024).toFixed(1)}KB → ${(compressedSize / 1024).toFixed(1)}KB)`
+    };
+  } catch (error) {
+    return { success: false, error: error.message };
+  }
+}
+
+async function pdfRotate(data) {
+  try {
+    const pdfBytes = fs.readFileSync(data.inputPath);
+    const pdf = await PDFDocument.load(pdfBytes);
+    const totalPages = pdf.getPageCount();
+
+    let pagesToRotate = [];
+    if (data.pages && data.pages.trim()) {
+      pagesToRotate = parsePageRanges(data.pages, totalPages);
+    } else {
+      pagesToRotate = Array.from({ length: totalPages }, (_, i) => i);
+    }
+
+    pagesToRotate.forEach(pageIndex => {
+      const page = pdf.getPage(pageIndex);
+      page.setRotation(degrees(data.angle));
+    });
+
+    const rotatedPdfBytes = await pdf.save();
+    fs.writeFileSync(data.outputPath, rotatedPdfBytes);
+
+    return {
+      success: true,
+      message: `Successfully rotated ${pagesToRotate.length} page(s) by ${data.angle}\u00B0`
+    };
+  } catch (error) {
+    return { success: false, error: error.message };
+  }
+}
+
+async function pdfDeletePages(data) {
+  try {
+    const pdfBytes = fs.readFileSync(data.inputPath);
+    const pdf = await PDFDocument.load(pdfBytes);
+    const totalPages = pdf.getPageCount();
+
+    const pagesToDelete = parsePageRanges(data.pages, totalPages);
+
+    pagesToDelete.sort((a, b) => b - a).forEach(pageIndex => {
+      pdf.removePage(pageIndex);
+    });
+
+    const newPdfBytes = await pdf.save();
+    fs.writeFileSync(data.outputPath, newPdfBytes);
+
+    return {
+      success: true,
+      message: `Successfully deleted ${pagesToDelete.length} page(s). New PDF has ${totalPages - pagesToDelete.length} pages`
+    };
+  } catch (error) {
+    return { success: false, error: error.message };
+  }
+}
+
+async function pdfReorder(data) {
+  try {
+    const pdfBytes = fs.readFileSync(data.inputPath);
+    const pdf = await PDFDocument.load(pdfBytes);
+    const totalPages = pdf.getPageCount();
+
+    const newOrder = data.newOrder.split(',').map(n => parseInt(n.trim()) - 1);
+
+    if (newOrder.length !== totalPages) {
+      return { success: false, error: `New order must include all ${totalPages} pages` };
+    }
+
+    const newPdf = await PDFDocument.create();
+    const copiedPages = await newPdf.copyPages(pdf, newOrder);
+    copiedPages.forEach(page => newPdf.addPage(page));
+
+    const reorderedPdfBytes = await newPdf.save();
+    fs.writeFileSync(data.outputPath, reorderedPdfBytes);
+
+    return { success: true, message: 'Successfully reordered PDF pages' };
+  } catch (error) {
+    return { success: false, error: error.message };
+  }
+}
+
+async function pdfWatermark(data) {
+  try {
+    const pdfBytes = fs.readFileSync(data.inputPath);
+    const pdf = await PDFDocument.load(pdfBytes);
+    const totalPages = pdf.getPageCount();
+
+    let pagesToWatermark = [];
+    if (data.pages === 'all') {
+      pagesToWatermark = Array.from({ length: totalPages }, (_, i) => i);
+    } else if (data.pages === 'custom' && data.customPages) {
+      pagesToWatermark = parsePageRanges(data.customPages, totalPages);
+    }
+
+    const font = await pdf.embedFont(StandardFonts.Helvetica);
+    const color = hexToRgb(data.color);
+
+    for (const pageIndex of pagesToWatermark) {
+      const page = pdf.getPage(pageIndex);
+      const { width, height } = page.getSize();
+
+      let x, y, rotation = 0;
+
+      switch (data.position) {
+        case 'center':
+          x = width / 2;
+          y = height / 2;
+          break;
+        case 'diagonal':
+          x = width / 2;
+          y = height / 2;
+          rotation = 45;
+          break;
+        case 'top-left':
+          x = 50;
+          y = height - 50;
+          break;
+        case 'top-center':
+          x = width / 2;
+          y = height - 50;
+          break;
+        case 'top-right':
+          x = width - 50;
+          y = height - 50;
+          break;
+        case 'bottom-left':
+          x = 50;
+          y = 50;
+          break;
+        case 'bottom-center':
+          x = width / 2;
+          y = 50;
+          break;
+        case 'bottom-right':
+          x = width - 50;
+          y = 50;
+          break;
+        default:
+          x = width / 2;
+          y = height / 2;
+      }
+
+      page.drawText(data.text, {
+        x,
+        y,
+        size: data.fontSize,
+        font,
+        color: rgb(color.r, color.g, color.b),
+        opacity: data.opacity,
+        rotate: degrees(rotation)
+      });
+    }
+
+    const watermarkedPdfBytes = await pdf.save();
+    fs.writeFileSync(data.outputPath, watermarkedPdfBytes);
+
+    return {
+      success: true,
+      message: `Successfully added watermark to ${pagesToWatermark.length} page(s)`
+    };
+  } catch (error) {
+    return { success: false, error: error.message };
+  }
+}
+
+async function pdfEncrypt(data) {
+  try {
+    const pdfBytes = fs.readFileSync(data.inputPath);
+    const pdf = await PDFDocument.load(pdfBytes);
+
+    const encryptedPdfBytes = await pdf.save({
+      userPassword: data.userPassword,
+      ownerPassword: data.ownerPassword || data.userPassword,
+      permissions: {
+        printing: data.permissions.printing ? 'highResolution' : 'lowResolution',
+        modifying: data.permissions.modifying,
+        copying: data.permissions.copying,
+        annotating: data.permissions.annotating,
+        fillingForms: data.permissions.fillingForms,
+        contentAccessibility: data.permissions.contentAccessibility,
+        documentAssembly: data.permissions.documentAssembly
+      }
+    });
+
+    fs.writeFileSync(data.outputPath, encryptedPdfBytes);
+
+    return { success: true, message: 'Successfully added password protection to PDF' };
+  } catch (error) {
+    if (error.message.includes('encrypt') || error.message.includes('password')) {
+      return {
+        success: false,
+        error: 'PDF encryption requires pdf-lib with encryption support. This feature may not be available in the current version.'
+      };
+    }
+    return { success: false, error: error.message };
+  }
+}
+
+async function pdfDecrypt(data) {
+  try {
+    const pdfBytes = fs.readFileSync(data.inputPath);
+    const pdf = await PDFDocument.load(pdfBytes, { password: data.password });
+
+    const decryptedPdfBytes = await pdf.save();
+    fs.writeFileSync(data.outputPath, decryptedPdfBytes);
+
+    return { success: true, message: 'Successfully removed password protection from PDF' };
+  } catch (error) {
+    if (error.message.includes('password') || error.message.includes('encrypted')) {
+      return { success: false, error: 'Incorrect password or PDF is not encrypted' };
+    }
+    return { success: false, error: error.message };
+  }
+}
+
+async function pdfSetPermissions(data) {
+  try {
+    const pdfBytes = fs.readFileSync(data.inputPath);
+    const loadOptions = data.currentPassword ? { password: data.currentPassword } : {};
+    const pdf = await PDFDocument.load(pdfBytes, loadOptions);
+
+    const newPdfBytes = await pdf.save({
+      ownerPassword: data.ownerPassword,
+      permissions: {
+        printing: data.permissions.printing ? 'highResolution' : 'lowResolution',
+        modifying: data.permissions.modifying,
+        copying: data.permissions.copying,
+        annotating: data.permissions.annotating,
+        fillingForms: data.permissions.fillingForms,
+        contentAccessibility: data.permissions.contentAccessibility,
+        documentAssembly: data.permissions.documentAssembly
+      }
+    });
+
+    fs.writeFileSync(data.outputPath, newPdfBytes);
+
+    return { success: true, message: 'Successfully updated PDF permissions' };
+  } catch (error) {
+    if (error.message.includes('encrypt') || error.message.includes('permission')) {
+      return {
+        success: false,
+        error: 'PDF permissions require pdf-lib with encryption support. This feature may not be available in the current version.'
+      };
+    }
+    return { success: false, error: error.message };
+  }
+}
+
+function executeOperation(operation, data) {
+  switch (operation) {
+    case 'merge': return pdfMerge(data);
+    case 'split': return pdfSplit(data);
+    case 'compress': return pdfCompress(data);
+    case 'rotate': return pdfRotate(data);
+    case 'delete': return pdfDeletePages(data);
+    case 'reorder': return pdfReorder(data);
+    case 'watermark': return pdfWatermark(data);
+    case 'encrypt': return pdfEncrypt(data);
+    case 'decrypt': return pdfDecrypt(data);
+    case 'permissions': return pdfSetPermissions(data);
+    default: return Promise.resolve({ success: false, error: `Unknown operation: ${operation}` });
+  }
+}
+
+async function getPageCount(filePath) {
+  const pdfBytes = fs.readFileSync(filePath);
+  const pdf = await PDFDocument.load(pdfBytes);
+  return pdf.getPageCount();
+}
+
+module.exports = {
+  parsePageRanges,
+  hexToRgb,
+  pdfMerge,
+  pdfSplit,
+  pdfCompress,
+  pdfRotate,
+  pdfDeletePages,
+  pdfReorder,
+  pdfWatermark,
+  pdfEncrypt,
+  pdfDecrypt,
+  pdfSetPermissions,
+  executeOperation,
+  getPageCount
+};

src/plugins/built-in/_sample/index.js

@@ -0,0 +1,12 @@
+const { PluginAPI } = require('../../plugin-api');
+
+class SamplePlugin extends PluginAPI {
+  init(context) {
+    this.context = context;
+    context.commands.register('hello', 'Sample: Hello World', () => {
+      console.log('[SamplePlugin] Hello from the plugin system!');
+    });
+  }
+}
+
+module.exports = { Plugin: SamplePlugin };

src/plugins/built-in/_sample/manifest.json

@@ -0,0 +1,13 @@
+{
+  "id": "_sample",
+  "name": "Sample Plugin",
+  "version": "1.0.0",
+  "description": "Demonstrates the plugin system. Safe to delete.",
+  "icon": "puzzle",
+  "extensionPoints": {
+    "commands": [
+      { "id": "hello", "label": "Sample: Hello World", "shortcut": "" }
+    ]
+  },
+  "settings": []
+}

src/plugins/built-in/writing-studio/goal-tracker.js

@@ -0,0 +1,87 @@
+const HISTORY_KEY = 'plugins.writing-studio.history';
+
+class GoalTracker {
+  /**
+   * @param {object} store - { get(key), set(key, value) } settings backend
+   */
+  constructor(store) {
+    this.store = store;
+  }
+
+  _getHistory() {
+    const raw = this.store.get(HISTORY_KEY);
+    return raw ? JSON.parse(raw) : {};
+  }
+
+  _setHistory(history) {
+    this.store.set(HISTORY_KEY, JSON.stringify(history));
+  }
+
+  _setHistoryDay(dateStr, data) {
+    const history = this._getHistory();
+    history[dateStr] = data;
+    this._setHistory(history);
+  }
+
+  addWords(count) {
+    const today = new Date().toISOString().split('T')[0];
+    const history = this._getHistory();
+    if (!history[today]) {
+      history[today] = { words: 0, sessions: 0 };
+    }
+    history[today].words += count;
+    history[today].sessions += 1;
+    this._setHistory(history);
+  }
+
+  getDailyProgress(goal) {
+    const today = new Date().toISOString().split('T')[0];
+    const history = this._getHistory();
+    const written = history[today]?.words || 0;
+    return { written, goal, pct: goal > 0 ? Math.min(100, Math.round((written / goal) * 100)) : 0 };
+  }
+
+  getStreak(goal) {
+    const history = this._getHistory();
+    let streak = 0;
+    const d = new Date();
+    for (let i = 0; i < 365; i++) {
+      const key = d.toISOString().split('T')[0];
+      const day = history[key];
+      if (day && day.words >= goal) {
+        streak++;
+        d.setDate(d.getDate() - 1);
+      } else {
+        break;
+      }
+    }
+    return streak;
+  }
+
+  getLast30Days() {
+    const history = this._getHistory();
+    const days = [];
+    const d = new Date();
+    for (let i = 0; i < 30; i++) {
+      const key = d.toISOString().split('T')[0];
+      const day = history[key];
+      days.push({ date: key, words: day?.words || 0 });
+      d.setDate(d.getDate() - 1);
+    }
+    return days.reverse();
+  }
+
+  getWeeklyTotal() {
+    const history = this._getHistory();
+    let total = 0;
+    const d = new Date();
+    for (let i = 0; i < 7; i++) {
+      const key = d.toISOString().split('T')[0];
+      if (history[key]) total += history[key].words || 0;
+      d.setDate(d.getDate() - 1);
+    }
+    return total;
+  }
+}
+
+module.exports = { GoalTracker };

src/plugins/built-in/writing-studio/index.js

@@ -0,0 +1,102 @@
+const { PluginAPI } = require('../../../plugins/plugin-api');
+const { SprintEngine } = require('./sprint-engine');
+const { GoalTracker } = require('./goal-tracker');
+const { SnapshotManager } = require('./snapshot-manager');
+const { ProjectManager } = require('./project-manager');
+
+class WritingStudioPlugin extends PluginAPI {
+  init(context) {
+    this.context = context;
+
+    this.sprintEngine = new SprintEngine({
+      onEvent: (name, data) => context.events.emit(name, data)
+    });
+    this.goalTracker = new GoalTracker(context.settings);
+    this.snapshotManager = new SnapshotManager(context.settings);
+    this.projectManager = new ProjectManager({
+      readFile: (p) => context.ipc.invoke('read-file', p),
+      writeFile: (p, c) => context.ipc.invoke('write-file', p, c),
+      fileExists: (p) => context.ipc.invoke('path-exists', p),
+      listDir: (p) => context.ipc.invoke('list-directory', p)
+    });
+
+    this._engines = {
+      sprint: this.sprintEngine,
+      goals: this.goalTracker,
+      snapshots: this.snapshotManager,
+      projects: this.projectManager
+    };
+
+    this._registerCommands(context);
+    this._registerStatusBar(context);
+  }
+
+  _registerCommands(context) {
+    const { sprintEngine, snapshotManager, goalTracker } = this;
+
+    context.commands.register('start-sprint', 'Studio: Start Sprint', () => {
+      const duration = context.settings.get('sprintDuration') || 25;
+      const content = context.editor.getContent() || '';
+      const words = content.split(/\s+/).filter(Boolean).length;
+      sprintEngine.start(duration, words);
+    }, 'Ctrl+Alt+S');
+
+    context.commands.register('stop-sprint', 'Studio: Stop Sprint', () => {
+      if (!sprintEngine.isActive()) return;
+      const content = context.editor.getContent() || '';
+      const words = content.split(/\s+/).filter(Boolean).length;
+      const result = sprintEngine.stop(words);
+      goalTracker.addWords(result.wordDelta);
+      context.events.emit('sprint:stopped', result);
+    }, 'Ctrl+Alt+Shift+S');
+
+    context.commands.register('take-snapshot', 'Studio: Take Snapshot', () => {
+      const content = context.editor.getContent() || '';
+      snapshotManager.create(content, 'manual');
+      context.events.emit('snapshot:created', {});
+    }, 'Ctrl+Alt+N');
+
+    context.commands.register('restore-last-snapshot', 'Studio: Restore Last Snapshot', () => {
+      const snaps = snapshotManager.list();
+      if (snaps.length === 0) return;
+      const content = snapshotManager.restore(snaps[0].id);
+      context.editor.insertAtCursor(content);
+    }, 'Ctrl+Alt+Z');
+
+    context.commands.register('new-project', 'Studio: New Project', () => {
+      context.events.emit('studio:new-project', {});
+    });
+
+    context.commands.register('compile-manuscript', 'Studio: Compile Manuscript', () => {
+      context.events.emit('studio:compile', {});
+    }, 'Ctrl+Alt+E');
+
+    context.commands.register('proofread-document', 'Studio: Proofread Document', () => {
+      if (context.events.hasHandler('ai:analyze')) {
+        const content = context.editor.getContent() || '';
+        context.events.emit('ai:analyze', { text: content, type: 'grammar' });
+      }
+    }, 'Ctrl+Alt+G');
+  }
+
+  _registerStatusBar(context) {
+    context.statusBar.registerIndicator('word-goal', {
+      text: '0/1000',
+      tooltip: 'Daily word goal progress'
+    });
+    context.statusBar.registerIndicator('sprint-timer', {
+      text: '',
+      tooltip: 'Writing sprint timer'
+    });
+  }
+
+  deactivate() {
+    if (this._sprintInterval) clearInterval(this._sprintInterval);
+  }
+
+  getEngines() {
+    return this._engines;
+  }
+}
+
+module.exports = { Plugin: WritingStudioPlugin };

src/plugins/built-in/writing-studio/manifest.json

@@ -0,0 +1,31 @@
+{
+  "id": "writing-studio",
+  "name": "Writing Studio",
+  "version": "1.0.0",
+  "description": "Manuscript management, writing sprints, goal tracking, snapshots, and smart proofreading",
+  "icon": "pen-tool",
+  "extensionPoints": {
+    "sidebar": [
+      { "id": "manuscript", "title": "Manuscript", "order": 30 },
+      { "id": "goals", "title": "Goals", "order": 31 },
+      { "id": "snapshots", "title": "Snapshots", "order": 32 },
+      { "id": "proofread", "title": "Proofread", "order": 33 }
+    ],
+    "commands": [
+      { "id": "start-sprint", "label": "Studio: Start Sprint", "shortcut": "Ctrl+Alt+S" },
+      { "id": "stop-sprint", "label": "Studio: Stop Sprint", "shortcut": "Ctrl+Alt+Shift+S" },
+      { "id": "take-snapshot", "label": "Studio: Take Snapshot", "shortcut": "Ctrl+Alt+N" },
+      { "id": "restore-last-snapshot", "label": "Studio: Restore Last Snapshot", "shortcut": "Ctrl+Alt+Z" },
+      { "id": "new-project", "label": "Studio: New Project", "shortcut": "" },
+      { "id": "compile-manuscript", "label": "Studio: Compile Manuscript", "shortcut": "Ctrl+Alt+E" },
+      { "id": "proofread-document", "label": "Studio: Proofread Document", "shortcut": "Ctrl+Alt+G" }
+    ],
+    "statusBar": { "indicators": ["sprint-timer", "word-goal"] }
+  },
+  "settings": [
+    { "key": "dailyGoal", "type": "number", "default": 1000, "label": "Daily word goal" },
+    { "key": "sprintDuration", "type": "number", "default": 25, "label": "Sprint duration (min)" },
+    { "key": "autoSnapshotInterval", "type": "number", "default": 0, "label": "Auto-snapshot interval (min, 0=off)" },
+    { "key": "maxSnapshots", "type": "number", "default": 50, "label": "Max snapshots to keep" }
+  ]
+}

src/plugins/built-in/writing-studio/panels/goals-panel.js

@@ -0,0 +1,99 @@
+function renderGoalsPanel(container, { engines, settings }) {
+  const dailyGoal = settings.get('dailyGoal') || 1000;
+  const progress = engines.goals.getDailyProgress(dailyGoal);
+  const streak = engines.goals.getStreak(dailyGoal);
+  const weekly = engines.goals.getWeeklyTotal();
+  const last30 = engines.goals.getLast30Days();
+
+  container.replaceChildren();
+
+  const panel = document.createElement('div');
+  panel.className = 'ws-panel';
+
+  // Daily progress section
+  const section1 = document.createElement('div');
+  section1.className = 'ws-section';
+  const heading1 = document.createElement('h3');
+  heading1.className = 'ws-heading';
+  heading1.textContent = 'Daily Progress';
+  section1.appendChild(heading1);
+
+  const bar = document.createElement('div');
+  bar.className = 'ws-progress-bar';
+  const fill = document.createElement('div');
+  fill.className = 'ws-progress-fill';
+  fill.style.width = progress.pct + '%';
+  bar.appendChild(fill);
+  section1.appendChild(bar);
+
+  const row = document.createElement('div');
+  row.className = 'ws-stat-row';
+  const label = document.createElement('span');
+  label.textContent = progress.written.toLocaleString() + ' / ' + dailyGoal.toLocaleString() + ' words';
+  const pct = document.createElement('span');
+  pct.className = 'ws-pct';
+  pct.textContent = progress.pct + '%';
+  row.appendChild(label);
+  row.appendChild(pct);
+  section1.appendChild(row);
+  panel.appendChild(section1);
+
+  // Stats cards
+  const section2 = document.createElement('div');
+  section2.className = 'ws-section';
+  const grid = document.createElement('div');
+  grid.className = 'ws-stat-grid';
+
+  const streakCard = document.createElement('div');
+  streakCard.className = 'ws-stat-card';
+  const streakVal = document.createElement('span');
+  streakVal.className = 'ws-stat-value';
+  streakVal.textContent = String(streak);
+  const streakLbl = document.createElement('span');
+  streakLbl.className = 'ws-stat-label';
+  streakLbl.textContent = 'Day Streak';
+  streakCard.appendChild(streakVal);
+  streakCard.appendChild(streakLbl);
+
+  const weekCard = document.createElement('div');
+  weekCard.className = 'ws-stat-card';
+  const weekVal = document.createElement('span');
+  weekVal.className = 'ws-stat-value';
+  weekVal.textContent = weekly.toLocaleString();
+  const weekLbl = document.createElement('span');
+  weekLbl.className = 'ws-stat-label';
+  weekLbl.textContent = 'This Week';
+  weekCard.appendChild(weekVal);
+  weekCard.appendChild(weekLbl);
+
+  grid.appendChild(streakCard);
+  grid.appendChild(weekCard);
+  section2.appendChild(grid);
+  panel.appendChild(section2);
+
+  // 30-day chart
+  const section3 = document.createElement('div');
+  section3.className = 'ws-section';
+  const heading3 = document.createElement('h3');
+  heading3.className = 'ws-heading';
+  heading3.textContent = 'Last 30 Days';
+  section3.appendChild(heading3);
+
+  const chart = document.createElement('div');
+  chart.className = 'ws-chart';
+  const maxWords = Math.max(...last30.map(d => d.words), 1);
+  for (const day of last30) {
+    const barEl = document.createElement('div');
+    const height = Math.max(2, (day.words / maxWords) * 60);
+    barEl.className = 'ws-bar' + (day.words >= dailyGoal ? ' ws-bar-met' : '');
+    barEl.style.height = height + 'px';
+    barEl.title = day.date + ': ' + day.words + ' words';
+    chart.appendChild(barEl);
+  }
+  section3.appendChild(chart);
+  panel.appendChild(section3);
+
+  container.appendChild(panel);
+}
+
+module.exports = { renderGoalsPanel };

src/plugins/built-in/writing-studio/panels/manuscript-panel.js

@@ -0,0 +1,124 @@
+function renderManuscriptPanel(container, { engines, editor, settings }) {
+  const projectDir = settings.get('projectDir');
+
+  container.replaceChildren();
+  const panel = document.createElement('div');
+  panel.className = 'ws-panel';
+
+  if (!projectDir) {
+    const empty = document.createElement('div');
+    empty.className = 'ws-empty';
+    const p = document.createElement('p');
+    p.textContent = 'No manuscript project open';
+    empty.appendChild(p);
+    const btn = document.createElement('button');
+    btn.className = 'ws-btn ws-btn-primary';
+    btn.id = 'ws-new-project';
+    btn.textContent = 'New Project';
+    btn.addEventListener('click', () => {
+      const name = prompt('Project name:');
+      if (!name) return;
+      settings.set('projectDir', name);
+      renderManuscriptPanel(container, { engines, editor, settings });
+    });
+    empty.appendChild(btn);
+    panel.appendChild(empty);
+    container.appendChild(panel);
+    return;
+  }
+
+  const project = engines.projects.loadProject(projectDir);
+  if (!project) {
+    const empty = document.createElement('div');
+    empty.className = 'ws-empty';
+    const p = document.createElement('p');
+    p.textContent = 'Project not found at ' + projectDir;
+    empty.appendChild(p);
+    const btn = document.createElement('button');
+    btn.className = 'ws-btn';
+    btn.id = 'ws-clear-project';
+    btn.textContent = 'Clear Project';
+    btn.addEventListener('click', () => {
+      settings.set('projectDir', null);
+      renderManuscriptPanel(container, { engines, editor, settings });
+    });
+    empty.appendChild(btn);
+    panel.appendChild(empty);
+    container.appendChild(panel);
+    return;
+  }
+
+  const stats = engines.projects.getStats(projectDir);
+
+  // Project title + progress
+  const section1 = document.createElement('div');
+  section1.className = 'ws-section';
+  const heading = document.createElement('h3');
+  heading.className = 'ws-heading';
+  heading.textContent = project.title;
+  section1.appendChild(heading);
+
+  const bar = document.createElement('div');
+  bar.className = 'ws-progress-bar';
+  const fill = document.createElement('div');
+  fill.className = 'ws-progress-fill';
+  fill.style.width = stats.pctComplete + '%';
+  bar.appendChild(fill);
+  section1.appendChild(bar);
+
+  const row = document.createElement('div');
+  row.className = 'ws-stat-row';
+  const label = document.createElement('span');
+  label.textContent = stats.totalWords.toLocaleString() + ' / ' + stats.targetWords.toLocaleString() + ' words';
+  const pct = document.createElement('span');
+  pct.className = 'ws-pct';
+  pct.textContent = stats.pctComplete + '%';
+  row.appendChild(label);
+  row.appendChild(pct);
+  section1.appendChild(row);
+  panel.appendChild(section1);
+
+  // Chapters list
+  const section2 = document.createElement('div');
+  section2.className = 'ws-section';
+  const heading2 = document.createElement('h3');
+  heading2.className = 'ws-heading';
+  heading2.textContent = 'Chapters (' + project.chapters.length + ')';
+  section2.appendChild(heading2);
+
+  const chList = document.createElement('div');
+  chList.className = 'ws-chapter-list';
+  for (const ch of project.chapters) {
+    const item = document.createElement('div');
+    item.className = 'ws-chapter-item';
+    const title = document.createElement('span');
+    title.className = 'ws-chapter-title';
+    title.textContent = ch.title || ch.file;
+    const status = document.createElement('span');
+    status.className = 'ws-chapter-status ws-status-' + (ch.status || 'draft');
+    status.textContent = ch.status || 'draft';
+    item.appendChild(title);
+    item.appendChild(status);
+    chList.appendChild(item);
+  }
+  section2.appendChild(chList);
+  panel.appendChild(section2);
+
+  // Compile button
+  const section3 = document.createElement('div');
+  section3.className = 'ws-section';
+  const compileBtn = document.createElement('button');
+  compileBtn.className = 'ws-btn ws-btn-primary';
+  compileBtn.id = 'ws-compile';
+  compileBtn.textContent = 'Compile Manuscript';
+  compileBtn.addEventListener('click', () => {
+    const compiled = engines.projects.compileManuscript(projectDir);
+    editor.insertAtCursor(compiled);
+  });
+  section3.appendChild(compileBtn);
+  panel.appendChild(section3);
+
+  container.appendChild(panel);
+}
+
+module.exports = { renderManuscriptPanel };

src/plugins/built-in/writing-studio/panels/proofread-panel.js

@@ -0,0 +1,97 @@
+function renderProofreadPanel(container, { events, editor }) {
+  const hasAI = events.hasHandler('ai:analyze');
+
+  container.replaceChildren();
+
+  const panel = document.createElement('div');
+  panel.className = 'ws-panel';
+
+  const section = document.createElement('div');
+  section.className = 'ws-section';
+
+  const btn = document.createElement('button');
+  btn.className = 'ws-btn ws-btn-primary';
+  btn.id = 'ws-proofread';
+  btn.textContent = hasAI ? 'Check Document' : 'AI Plugin Required';
+  btn.disabled = !hasAI;
+  section.appendChild(btn);
+
+  if (!hasAI) {
+    const note = document.createElement('p');
+    note.className = 'ws-muted';
+    note.textContent = 'Install the AI Assistant plugin to enable proofreading.';
+    section.appendChild(note);
+  }
+  panel.appendChild(section);
+
+  const issuesList = document.createElement('div');
+  issuesList.className = 'ws-issues-list';
+  issuesList.id = 'ws-issues';
+  panel.appendChild(issuesList);
+
+  container.appendChild(panel);
+
+  if (!hasAI) return;
+
+  container.querySelector('#ws-proofread').addEventListener('click', () => {
+    const content = editor.getContent() || '';
+    events.emit('ai:analyze', {
+      text: content,
+      type: 'grammar',
+      callback: (result) => {
+        if (result && result.issues) {
+          renderIssues(issuesList, result.issues);
+        }
+      }
+    });
+  });
+}
+
+function renderIssues(container, issues) {
+  container.replaceChildren();
+  if (!issues || issues.length === 0) {
+    const p = document.createElement('p');
+    p.className = 'ws-muted';
+    p.textContent = 'No issues found.';
+    container.appendChild(p);
+    return;
+  }
+  for (let i = 0; i < issues.length; i++) {
+    const issue = issues[i];
+    const item = document.createElement('div');
+    item.className = 'ws-issue-item';
+
+    const type = document.createElement('div');
+    type.className = 'ws-issue-type';
+    type.textContent = (issue.type || 'grammar').toUpperCase();
+    item.appendChild(type);
+
+    const text = document.createElement('div');
+    text.className = 'ws-issue-text';
+    text.textContent = issue.message || issue.text || '';
+    item.appendChild(text);
+
+    if (issue.suggestion) {
+      const sug = document.createElement('div');
+      sug.className = 'ws-issue-suggestion';
+      sug.textContent = 'Suggestion: ' + issue.suggestion;
+      item.appendChild(sug);
+    }
+
+    const actions = document.createElement('div');
+    actions.className = 'ws-issue-actions';
+    for (const [action, label] of [['accept', 'Accept'], ['dismiss', 'Dismiss']]) {
+      const actionBtn = document.createElement('button');
+      actionBtn.className = 'ws-btn ws-btn-sm';
+      actionBtn.textContent = label;
+      actionBtn.addEventListener('click', () => {
+        item.remove();
+      });
+      actions.appendChild(actionBtn);
+    }
+    item.appendChild(actions);
+    container.appendChild(item);
+  }
+}
+
+module.exports = { renderProofreadPanel };

src/plugins/built-in/writing-studio/panels/snapshots-panel.js

@@ -0,0 +1,81 @@
+function renderSnapshotsPanel(container, { engines, editor }) {
+  const snapshots = engines.snapshots.list();
+
+  container.replaceChildren();
+
+  const panel = document.createElement('div');
+  panel.className = 'ws-panel';
+
+  // Header with take snapshot button
+  const section = document.createElement('div');
+  section.className = 'ws-section';
+  const btn = document.createElement('button');
+  btn.className = 'ws-btn ws-btn-primary';
+  btn.id = 'ws-take-snapshot';
+  btn.textContent = 'Take Snapshot';
+  section.appendChild(btn);
+  const count = document.createElement('span');
+  count.className = 'ws-muted';
+  count.textContent = snapshots.length + ' snapshots';
+  section.appendChild(count);
+  panel.appendChild(section);
+
+  // Snapshot list
+  const list = document.createElement('div');
+  list.className = 'ws-snapshot-list';
+  for (const s of snapshots) {
+    const item = document.createElement('div');
+    item.className = 'ws-snapshot-item';
+
+    const header = document.createElement('div');
+    header.className = 'ws-snapshot-header';
+    const sLabel = document.createElement('span');
+    sLabel.className = 'ws-snapshot-label';
+    sLabel.textContent = s.label;
+    const sWords = document.createElement('span');
+    sWords.textContent = s.wordCount + ' words';
+    header.appendChild(sLabel);
+    header.appendChild(sWords);
+    item.appendChild(header);
+
+    const time = document.createElement('div');
+    time.className = 'ws-snapshot-time';
+    time.textContent = new Date(s.timestamp).toLocaleString();
+    item.appendChild(time);
+
+    const actions = document.createElement('div');
+    actions.className = 'ws-snapshot-actions';
+    for (const [action, text, cls] of [['restore', 'Restore', ''], ['diff', 'Diff', ''], ['delete', 'Delete', 'ws-btn-danger']]) {
+      const actionBtn = document.createElement('button');
+      actionBtn.className = 'ws-btn ws-btn-sm' + (cls ? ' ' + cls : '');
+      actionBtn.textContent = text;
+      actionBtn.addEventListener('click', () => {
+        if (action === 'restore') {
+          const content = engines.snapshots.restore(s.id);
+          editor.insertAtCursor(content);
+        } else if (action === 'delete') {
+          engines.snapshots.delete(s.id);
+          renderSnapshotsPanel(container, { engines, editor });
+        } else if (action === 'diff') {
+          const current = editor.getContent() || '';
+          const result = engines.snapshots.diff(s.id, current);
+          alert('+' + result.added + ' lines added, -' + result.removed + ' lines removed');
+        }
+      });
+      actions.appendChild(actionBtn);
+    }
+    item.appendChild(actions);
+    list.appendChild(item);
+  }
+  panel.appendChild(list);
+  container.appendChild(panel);
+
+  // Take snapshot button handler
+  container.querySelector('#ws-take-snapshot').addEventListener('click', () => {
+    const content = editor.getContent() || '';
+    engines.snapshots.create(content, 'manual');
+    renderSnapshotsPanel(container, { engines, editor });
+  });
+}
+
+module.exports = { renderSnapshotsPanel };

src/plugins/built-in/writing-studio/project-manager.js

@@ -0,0 +1,74 @@
+class ProjectManager {
+  /**
+   * @param {object} fs - { readFile(path), writeFile(path, content), fileExists(path), listDir(path) }
+   */
+  constructor(fs) {
+    this.fs = fs;
+  }
+
+  createProject(dir, opts) {
+    const project = {
+      title: opts.title,
+      type: opts.type || 'manuscript',
+      target: { words: opts.targetWords || 0, deadline: opts.deadline || null },
+      chapters: [],
+      metadata: opts.metadata || {}
+    };
+    this.fs.writeFile(dir + '/.project.json', JSON.stringify(project, null, 2));
+    return project;
+  }
+
+  loadProject(dir) {
+    const raw = this.fs.readFile(dir + '/.project.json');
+    if (!raw) return null;
+    return JSON.parse(raw);
+  }
+
+  _saveProject(dir, project) {
+    this.fs.writeFile(dir + '/.project.json', JSON.stringify(project, null, 2));
+  }
+
+  addChapter(dir, chapter) {
+    const project = this.loadProject(dir);
+    if (!project) throw new Error('Project not found');
+    project.chapters.push(chapter);
+    this._saveProject(dir, project);
+  }
+
+  updateChapter(dir, index, updates) {
+    const project = this.loadProject(dir);
+    if (!project) throw new Error('Project not found');
+    Object.assign(project.chapters[index], updates);
+    this._saveProject(dir, project);
+  }
+
+  compileManuscript(dir) {
+    const project = this.loadProject(dir);
+    if (!project) throw new Error('Project not found');
+    const parts = [];
+    for (const ch of project.chapters) {
+      const content = this.fs.readFile(dir + '/' + ch.file);
+      if (content) parts.push(content);
+    }
+    return parts.join('\n\n---\n\n');
+  }
+
+  getStats(dir) {
+    const project = this.loadProject(dir);
+    if (!project) throw new Error('Project not found');
+    let totalWords = 0;
+    for (const ch of project.chapters) {
+      const content = this.fs.readFile(dir + '/' + ch.file);
+      if (content) totalWords += content.split(/\s+/).filter(Boolean).length;
+    }
+    const target = project.target.words || 0;
+    return {
+      totalWords,
+      chapterCount: project.chapters.length,
+      targetWords: target,
+      pctComplete: target > 0 ? Math.min(100, Math.round((totalWords / target) * 100)) : 0
+    };
+  }
+}
+
+module.exports = { ProjectManager };

src/plugins/built-in/writing-studio/snapshot-manager.js

@@ -0,0 +1,73 @@
+class SnapshotManager {
+  /**
+   * @param {object} store - { get(key), set(key, value) }
+   * @param {string} storeKey - settings key for snapshots
+   */
+  constructor(store, storeKey = 'plugins.writing-studio.snapshots') {
+    this.store = store;
+    this.storeKey = storeKey;
+  }
+
+  _getAll() {
+    const raw = this.store.get(this.storeKey);
+    return raw ? JSON.parse(raw) : [];
+  }
+
+  _saveAll(snaps) {
+    this.store.set(this.storeKey, JSON.stringify(snaps));
+  }
+
+  create(content, label = 'manual') {
+    const snaps = this._getAll();
+    const snap = {
+      id: 'snap-' + Date.now() + '-' + Math.random().toString(36).slice(2, 8),
+      timestamp: new Date().toISOString(),
+      content,
+      wordCount: content.split(/\s+/).filter(Boolean).length,
+      label
+    };
+    snaps.unshift(snap);
+    this._saveAll(snaps);
+    return snap;
+  }
+
+  list() {
+    return this._getAll();
+  }
+
+  getById(id) {
+    return this._getAll().find(s => s.id === id) || null;
+  }
+
+  restore(id) {
+    const snap = this.getById(id);
+    if (!snap) throw new Error('Snapshot not found');
+    return snap.content;
+  }
+
+  delete(id) {
+    const snaps = this._getAll().filter(s => s.id !== id);
+    this._saveAll(snaps);
+  }
+
+  diff(id, currentContent) {
+    const snap = this.getById(id);
+    if (!snap) throw new Error('Snapshot not found');
+    const oldLines = snap.content.split('\n');
+    const newLines = currentContent.split('\n');
+    const oldSet = new Set(oldLines);
+    const newSet = new Set(newLines);
+    let added = 0;
+    let removed = 0;
+    for (const line of newLines) { if (!oldSet.has(line)) added++; }
+    for (const line of oldLines) { if (!newSet.has(line)) removed++; }
+    return { added, removed };
+  }
+
+  prune(keepCount) {
+    const snaps = this._getAll();
+    this._saveAll(snaps.slice(0, keepCount));
+  }
+}
+
+module.exports = { SnapshotManager };

src/plugins/built-in/writing-studio/sprint-engine.js

@@ -0,0 +1,51 @@
+class SprintEngine {
+  /**
+   * @param {object} opts
+   * @param {function} opts.onEvent - callback(event_name, data)
+   */
+  constructor(opts = {}) {
+    this.onEvent = opts.onEvent || (() => {});
+    this._active = false;
+    this._startTime = null;
+    this._duration = 0;
+    this._initialWords = 0;
+  }
+
+  start(durationMinutes, currentWordCount) {
+    if (this._active) throw new Error('Sprint already active');
+    this._active = true;
+    this._startTime = Date.now();
+    this._duration = durationMinutes * 60 * 1000;
+    this._initialWords = currentWordCount;
+  }
+
+  stop(currentWordCount) {
+    if (!this._active) throw new Error('No active sprint');
+    const elapsed = Date.now() - this._startTime;
+    const wordDelta = Math.max(0, currentWordCount - this._initialWords);
+    const elapsedMinutes = elapsed / 60000;
+    const wpm = elapsedMinutes > 0 ? Math.round(wordDelta / elapsedMinutes) : 0;
+    this._active = false;
+    this._startTime = null;
+    return { wordDelta, elapsed, wpm };
+  }
+
+  tick(elapsedMs) {
+    if (!this._active) return;
+    const remaining = Math.max(0, this._duration - elapsedMs);
+    this.onEvent('sprint:tick', { remaining, elapsed: elapsedMs });
+    if (remaining <= 0) {
+      this._active = false;
+      this.onEvent('sprint:complete', { expired: true });
+    }
+  }
+
+  isActive() { return this._active; }
+
+  getRemaining() {
+    if (!this._active) return 0;
+    return Math.max(0, this._duration - (Date.now() - this._startTime));
+  }
+}
+
+module.exports = { SprintEngine };

src/plugins/event-bus.js

@@ -0,0 +1,43 @@
+class EventBus {
+  constructor() {
+    this.listeners = new Map();
+  }
+
+  on(event, handler) {
+    if (!this.listeners.has(event)) {
+      this.listeners.set(event, []);
+    }
+    this.listeners.get(event).push(handler);
+  }
+
+  off(event, handler) {
+    if (!handler) {
+      this.listeners.delete(event);
+      return;
+    }
+    const handlers = this.listeners.get(event);
+    if (handlers) {
+      const idx = handlers.indexOf(handler);
+      if (idx !== -1) handlers.splice(idx, 1);
+    }
+  }
+
+  emit(event, payload) {
+    const handlers = this.listeners.get(event);
+    if (!handlers) return;
+    for (const handler of handlers) {
+      try {
+        handler(payload);
+      } catch (err) {
+        console.error(`[EventBus] Error in handler for "${event}":`, err);
+      }
+    }
+  }
+
+  hasHandler(event) {
+    const handlers = this.listeners.get(event);
+    return handlers !== undefined && handlers !== null && handlers.length > 0;
+  }
+}
+
+module.exports = { EventBus };

src/plugins/plugin-api.js

@@ -0,0 +1,23 @@
+class PluginAPI {
+  /**
+   * Called when the plugin is discovered and loaded.
+   * Receives a scoped context object with APIs.
+   * @param {object} context - Plugin context (sidebar, commands, settings, etc.)
+   */
+  init(context) {
+    this.context = context;
+  }
+
+  /** Called when the plugin is activated (e.g., sidebar panel clicked). */
+  activate() {}
+
+  /** Called when the plugin is deactivated. */
+  deactivate() {}
+
+  /** Returns the parsed manifest.json for this plugin. */
+  getManifest() {
+    return this._manifest || null;
+  }
+}
+
+module.exports = { PluginAPI };

src/plugins/plugin-context.js

@@ -0,0 +1,70 @@
+class PluginContext {
+  /**
+   * @param {object} deps - Injected dependencies
+   * @param {string} deps.pluginId - Plugin unique ID (for namespacing)
+   * @param {object} deps.sidebar - SidebarManager.registerPanel
+   * @param {object} deps.commands - CommandPalette.register
+   * @param {object} deps.statusBar - StatusBar.registerIndicator
+   * @param {object} deps.eventBus - EventBus instance
+   * @param {object} deps.settings - { get, set, onChanged }
+   * @param {object} deps.editor - { getContent, getSelection, insertAtCursor, onContentChanged }
+   * @param {object} deps.ipc - { invoke, on }
+   * @param {object} deps.exportHooks - { preHooks: [], postHooks: [] }
+   */
+  constructor(deps) {
+    const { pluginId, sidebar, commands, statusBar, eventBus, settings, editor, ipc, exportHooks } = deps;
+
+    this.sidebar = {
+      registerPanel: (id, opts) => sidebar.registerPanel(`${pluginId}:${id}`, opts)
+    };
+
+    this.commands = {
+      register: (id, label, handler, shortcut) => {
+        const safeHandler = (...args) => {
+          try {
+            handler(...args);
+          } catch (err) {
+            console.error(`[Plugin:${pluginId}] Command "${id}" error:`, err);
+          }
+        };
+        commands.register(`${pluginId}:${id}`, label, safeHandler, shortcut);
+      }
+    };
+
+    this.statusBar = {
+      registerIndicator: (id, opts) => statusBar.registerIndicator(`${pluginId}:${id}`, opts)
+    };
+
+    this.settings = {
+      get: (key) => settings.get(`plugins.${pluginId}.${key}`),
+      set: (key, value) => settings.set(`plugins.${pluginId}.${key}`, value),
+      onChanged: (key, cb) => settings.onChanged(`plugins.${pluginId}.${key}`, cb)
+    };
+
+    this.editor = {
+      getContent: () => editor.getContent(),
+      getSelection: () => editor.getSelection(),
+      insertAtCursor: (text) => editor.insertAtCursor(text),
+      onContentChanged: (cb) => editor.onContentChanged(cb)
+    };
+
+    this.events = {
+      on: (event, handler) => eventBus.on(event, handler),
+      off: (event, handler) => eventBus.off(event, handler),
+      emit: (event, payload) => eventBus.emit(event, payload),
+      hasHandler: (event) => eventBus.hasHandler(event)
+    };
+
+    this.ipc = {
+      invoke: (channel, ...args) => ipc.invoke(channel, ...args),
+      on: (channel, handler) => ipc.on(channel, handler)
+    };
+
+    this.exports = {
+      registerPreHook: (handler) => { if (exportHooks) exportHooks.preHooks.push(handler); },
+      registerPostHook: (handler) => { if (exportHooks) exportHooks.postHooks.push(handler); }
+    };
+  }
+}
+
+module.exports = { PluginContext };

src/plugins/plugin-loader.js

@@ -0,0 +1,75 @@
+const fs = require('fs');
+const path = require('path');
+
+class PluginLoader {
+  /**
+   * @param {string[]} searchDirs - Directories to scan for plugin folders
+   */
+  constructor(searchDirs = []) {
+    this.searchDirs = searchDirs;
+    this.loadedIds = new Set();
+  }
+
+  /**
+   * Discover plugins by scanning searchDirs for manifest.json files.
+   * Returns array of { id, name, version, description, manifest, PluginClass, dir }
+   */
+  discoverPlugins() {
+    const plugins = [];
+    for (const dir of this.searchDirs) {
+      if (!fs.existsSync(dir)) continue;
+      const entries = fs.readdirSync(dir, { withFileTypes: true });
+      for (const entry of entries) {
+        if (!entry.isDirectory()) continue;
+        const pluginDir = path.join(dir, entry.name);
+        const manifestPath = path.join(pluginDir, 'manifest.json');
+        if (!fs.existsSync(manifestPath)) continue;
+        try {
+          const raw = fs.readFileSync(manifestPath, 'utf-8');
+          const manifest = JSON.parse(raw);
+          this.validateManifest(manifest);
+          let PluginClass = null;
+          const indexPath = path.join(pluginDir, 'index.js');
+          if (fs.existsSync(indexPath)) {
+            try {
+              const loaded = require(indexPath);
+              PluginClass = loaded.Plugin || loaded.default || null;
+            } catch (err) {
+              console.error(`[PluginLoader] Failed to load index.js for "${manifest.id}":`, err.message);
+              continue;
+            }
+          }
+          plugins.push({
+            id: manifest.id,
+            name: manifest.name,
+            version: manifest.version,
+            description: manifest.description,
+            manifest,
+            PluginClass,
+            dir: pluginDir
+          });
+          this.loadedIds.add(manifest.id);
+        } catch (err) {
+          console.error(`[PluginLoader] Skipping plugin in ${pluginDir}:`, err.message);
+        }
+      }
+    }
+    return plugins;
+  }
+
+  /**
+   * Validate a manifest object. Throws on invalid.
+   */
+  validateManifest(manifest) {
+    if (!manifest.id) throw new Error('Manifest missing required field: id');
+    if (!manifest.name) throw new Error('Manifest missing required field: name');
+    if (!manifest.version) throw new Error('Manifest missing required field: version');
+    if (!manifest.description) throw new Error('Manifest missing required field: description');
+    if (this.loadedIds.has(manifest.id)) {
+      throw new Error(`Duplicate plugin id: "${manifest.id}"`);
+    }
+    return true;
+  }
+}
+
+module.exports = { PluginLoader };

src/plugins/plugin-registry.js

@@ -0,0 +1,80 @@
+const { PluginContext } = require('./plugin-context');
+const { PluginAPI } = require('./plugin-api');
+
+class PluginRegistry {
+  constructor(deps) {
+    this.deps = deps;
+    this.plugins = new Map();
+    this.exportHooks = { preHooks: [], postHooks: [] };
+  }
+
+  /**
+   * Register a discovered plugin. Creates instance, builds context, calls init.
+   * If init throws, plugin is NOT registered.
+   */
+  register(pluginInfo) {
+    const { id, name, version, description, manifest, PluginClass, dir } = pluginInfo;
+
+    let instance;
+    if (PluginClass) {
+      instance = new PluginClass();
+    } else {
+      instance = new PluginAPI();
+    }
+    instance._manifest = manifest;
+
+    const context = new PluginContext({
+      pluginId: id,
+      sidebar: this.deps.sidebar,
+      commands: this.deps.commands,
+      statusBar: this.deps.statusBar,
+      eventBus: this.deps.eventBus,
+      settings: this.deps.settings,
+      editor: this.deps.editor,
+      ipc: this.deps.ipc,
+      exportHooks: this.exportHooks
+    });
+
+    try {
+      instance.init(context);
+    } catch (err) {
+      console.error(`[PluginRegistry] Plugin "${id}" init failed:`, err.message);
+      return;
+    }
+
+    this.plugins.set(id, { id, name, version, description, manifest, instance, dir, context });
+    console.log(`[PluginRegistry] Registered plugin: ${name} v${version}`);
+  }
+
+  getPlugin(id) {
+    return this.plugins.get(id);
+  }
+
+  getAll() {
+    return Array.from(this.plugins.values());
+  }
+
+  activate(id) {
+    const plugin = this.plugins.get(id);
+    if (plugin?.instance) {
+      try {
+        plugin.instance.activate();
+      } catch (err) {
+        console.error(`[PluginRegistry] Plugin "${id}" activate error:`, err.message);
+      }
+    }
+  }
+
+  deactivate(id) {
+    const plugin = this.plugins.get(id);
+    if (plugin?.instance) {
+      try {
+        plugin.instance.deactivate();
+      } catch (err) {
+        console.error(`[PluginRegistry] Plugin "${id}" deactivate error:`, err.message);
+      }
+    }
+  }
+}
+
+module.exports = { PluginRegistry };

src/plugins/settings-store.js

@@ -0,0 +1,23 @@
+class SettingsStore {
+  /**
+   * @param {object} backend - { get(key), set(key, value) } backed by main process store
+   */
+  constructor(backend) {
+    this.backend = backend;
+  }
+
+  get(key) {
+    return this.backend.get(key);
+  }
+
+  set(key, value) {
+    this.backend.set(key, value);
+  }
+
+  onChanged(key, callback) {
+    // Deferred: plugins read settings on init/activate for MVP.
+    // Full change notification requires IPC watcher in main process.
+  }
+}
+
+module.exports = { SettingsStore };

src/preload.js

@@ -0,0 +1,447 @@
+/**
+ * Preload Script for PanConverter
+ *
+ * This script creates a secure bridge between the main process and renderer process.
+ * It exposes only specific IPC channels, preventing direct Node.js access in the renderer.
+ *
+ * Security Benefits:
+ * - No direct access to Node.js APIs (fs, path, child_process, etc.)
+ * - All IPC channels are explicitly whitelisted
+ * - Prevents XSS from escalating to full system access
+ *
+ * @version 4.4.1
+ */
+
+const { contextBridge, ipcRenderer } = require('electron');
+
+// Define allowed IPC channels for security
+const ALLOWED_SEND_CHANNELS = [
+  // File operations
+  'save-file',
+  'save-current-file',
+  'set-current-file',
+  'save-recent-files',
+  'clear-recent-files',
+  'renderer-ready',
+  'select-custom-css',
+
+  // Theme
+  'get-theme',
+
+  // Print
+  'do-print',
+  'do-print-with-options',
+
+  // Export
+  'export-with-options',
+  'export-spreadsheet',
+
+  // Batch conversion
+  'batch-convert',
+  'select-folder',
+
+  // Universal converter
+  'universal-convert',
+  'universal-convert-batch',
+
+  // Image converter
+  'image-convert',
+  'image-batch-convert',
+  'image-resize',
+  'image-compress',
+  'image-rotate',
+
+  // Audio converter
+  'audio-convert',
+  'audio-batch-convert',
+  'audio-extract',
+  'audio-trim',
+  'audio-merge',
+
+  // Video converter
+  'video-convert',
+  'video-batch-convert',
+  'video-compress',
+  'video-trim',
+  'video-frames',
+  'video-gif',
+
+  // Header/Footer
+  'get-header-footer-settings',
+  'save-header-footer-settings',
+  'browse-header-footer-logo',
+  'save-header-footer-logo',
+  'clear-header-footer-logo',
+
+  // Page settings
+  'get-page-settings',
+  'update-page-settings',
+
+  // Template settings
+  'set-custom-start-page',
+
+  // PDF operations
+  'process-pdf-operation',
+  'get-pdf-page-count',
+  'select-pdf-folder',
+
+  // ASCII generator (separate window)
+  'open-ascii-generator',
+
+  // Table generator (separate window)
+  'open-table-generator',
+
+  // Insert generated content
+  'insert-generated-content',
+
+  // Image paste/drop
+  'save-pasted-image',
+
+  // Templates
+  'load-template',
+
+  // File Explorer
+  'list-directory',
+  'read-file',
+  'write-file',
+  'delete-file',
+  'ensure-directory',
+  'path-exists',
+  'is-directory',
+  'copy-path',
+  'move-path',
+
+  // Git
+  'git-status',
+  'git-stage',
+  'git-commit',
+  'git-log',
+
+  // Snippets
+  'get-snippets',
+  'save-snippet',
+  'delete-snippet',
+
+  // Code execution (REPL)
+  'execute-code',
+
+  // File open by path
+  'open-file-path',
+
+  // PDF editor from toolbar
+  'show-pdf-editor-from-toolbar',
+
+  // Menu triggers
+  'menu-open',
+  'export',
+
+  // Git diff
+  'git-diff',
+
+  // Plugin settings
+  'plugin-settings:get',
+  'plugin-settings:set'
+];
+
+const ALLOWED_RECEIVE_CHANNELS = [
+  // File operations
+  'file-new',
+  'file-opened',
+  'file-save',
+  'get-content-for-save',
+  'get-content-for-spreadsheet',
+  'recent-files-cleared',
+  'load-custom-css',
+  'clear-custom-css',
+
+  // UI toggles
+  'toggle-preview',
+  'toggle-find',
+
+  // Theme
+  'theme-changed',
+  'theme-data',
+
+  // Edit operations
+  'undo',
+  'redo',
+
+  // Font
+  'adjust-font-size',
+
+  // Print
+  'print-preview',
+  'print-preview-styled',
+
+  // Export dialogs
+  'show-export-dialog',
+  'show-batch-dialog',
+  'show-universal-converter-dialog',
+  'show-table-generator',
+  'show-pdf-editor-dialog',
+
+  // Converter dialogs
+  'show-image-converter',
+  'show-audio-converter',
+  'show-video-converter',
+
+  // PDF viewer
+  'open-pdf-viewer',
+
+  // Conversion status
+  'conversion-status',
+  'conversion-complete',
+  'batch-progress',
+  'image-conversion-complete',
+  'audio-conversion-complete',
+  'video-conversion-complete',
+
+  // Folder selection
+  'folder-selected',
+  'pdf-folder-selected',
+
+  // Header/Footer
+  'header-footer-settings-data',
+  'header-footer-logo-selected',
+  'header-footer-logo-saved',
+
+  // Page settings
+  'page-settings-data',
+
+  // PDF operations
+  'pdf-page-count',
+  'pdf-operation-complete',
+  'pdf-operation-error',
+
+  // ASCII Art Generator
+  'show-ascii-generator-window',
+  'show-ascii-generator',
+
+  // Table Generator
+  'show-table-generator-window',
+
+  // Header/Footer dialog
+  'open-header-footer-dialog',
+  'header-footer-logo-cleared',
+
+  // PDF operation progress
+  'pdf-operation-progress',
+
+  // Insert content from generator windows
+  'insert-content',
+
+  // Batch converter
+  'show-batch-converter',
+
+  // v4 menu-triggered events
+  'load-template-menu',
+  'toggle-command-palette',
+  'toggle-sidebar-panel',
+  'toggle-bottom-panel'
+];
+
+/**
+ * Secure API exposed to renderer process
+ * Access via window.electronAPI in renderer
+ */
+contextBridge.exposeInMainWorld('electronAPI', {
+  // ============================================
+  // SEND METHODS (Renderer -> Main)
+  // ============================================
+
+  /**
+   * Send a message to the main process
+   * @param {string} channel - IPC channel name
+   * @param {any} data - Data to send
+   */
+  send: (channel, data) => {
+    if (ALLOWED_SEND_CHANNELS.includes(channel)) {
+      ipcRenderer.send(channel, data);
+    } else {
+      console.warn(`[Preload] Blocked send to unauthorized channel: ${channel}`);
+    }
+  },
+
+  /**
+   * Invoke a main process handler and get a response
+   * @param {string} channel - IPC channel name
+   * @param {any} data - Data to send
+   * @returns {Promise<any>} Response from main process
+   */
+  invoke: async (channel, data) => {
+    if (ALLOWED_SEND_CHANNELS.includes(channel)) {
+      return await ipcRenderer.invoke(channel, data);
+    } else {
+      console.warn(`[Preload] Blocked invoke to unauthorized channel: ${channel}`);
+      return null;
+    }
+  },
+
+  // ============================================
+  // RECEIVE METHODS (Main -> Renderer)
+  // ============================================
+
+  /**
+   * Register a listener for messages from main process
+   * @param {string} channel - IPC channel name
+   * @param {Function} callback - Function to call with received data
+   * @returns {Function} Cleanup function to remove listener
+   */
+  on: (channel, callback) => {
+    if (ALLOWED_RECEIVE_CHANNELS.includes(channel)) {
+      const subscription = (event, ...args) => callback(...args);
+      ipcRenderer.on(channel, subscription);
+
+      // Return cleanup function
+      return () => {
+        ipcRenderer.removeListener(channel, subscription);
+      };
+    } else {
+      console.warn(`[Preload] Blocked listener for unauthorized channel: ${channel}`);
+      return () => {}; // No-op cleanup
+    }
+  },
+
+  /**
+   * Register a one-time listener for messages from main process
+   * @param {string} channel - IPC channel name
+   * @param {Function} callback - Function to call with received data
+   */
+  once: (channel, callback) => {
+    if (ALLOWED_RECEIVE_CHANNELS.includes(channel)) {
+      ipcRenderer.once(channel, (event, ...args) => callback(...args));
+    } else {
+      console.warn(`[Preload] Blocked once listener for unauthorized channel: ${channel}`);
+    }
+  },
+
+  /**
+   * Remove all listeners for a channel
+   * @param {string} channel - IPC channel name
+   */
+  removeAllListeners: (channel) => {
+    if (ALLOWED_RECEIVE_CHANNELS.includes(channel)) {
+      ipcRenderer.removeAllListeners(channel);
+    }
+  },
+
+  // ============================================
+  // CONVENIENCE METHODS
+  // ============================================
+
+  // File Operations
+  file: {
+    save: (filePath, content) => ipcRenderer.send('save-file', { path: filePath, content }),
+    saveCurrent: (content) => ipcRenderer.send('save-current-file', content),
+    setCurrent: (filePath) => ipcRenderer.send('set-current-file', filePath),
+    saveRecent: (recentFiles) => ipcRenderer.send('save-recent-files', recentFiles),
+    clearRecent: () => ipcRenderer.send('clear-recent-files'),
+    rendererReady: () => ipcRenderer.send('renderer-ready'),
+    read: (filePath) => ipcRenderer.invoke('read-file', filePath),
+    write: (filePath, content) => ipcRenderer.invoke('write-file', { path: filePath, content }),
+    delete: (filePath) => ipcRenderer.invoke('delete-file', filePath),
+    ensureDir: (dirPath) => ipcRenderer.invoke('ensure-directory', dirPath),
+    exists: (filePath) => ipcRenderer.invoke('path-exists', filePath),
+    isDirectory: (filePath) => ipcRenderer.invoke('is-directory', filePath),
+    copy: (source, destination) => ipcRenderer.invoke('copy-path', { source, destination }),
+    move: (source, destination) => ipcRenderer.invoke('move-path', { source, destination })
+  },
+
+  // Theme Operations
+  theme: {
+    get: () => ipcRenderer.send('get-theme')
+  },
+
+  // Print Operations
+  print: {
+    doPrint: (options) => ipcRenderer.send('do-print', options)
+  },
+
+  // Export Operations
+  export: {
+    withOptions: (format, options) => ipcRenderer.send('export-with-options', { format, options }),
+    spreadsheet: (content, format) => ipcRenderer.send('export-spreadsheet', { content, format })
+  },
+
+  // Batch Conversion
+  batch: {
+    convert: (inputFolder, outputFolder, format, options) => {
+      ipcRenderer.send('batch-convert', { inputFolder, outputFolder, format, options });
+    },
+    selectFolder: (type) => ipcRenderer.send('select-folder', type)
+  },
+
+  // Universal Converter
+  converter: {
+    convert: (tool, fromFormat, toFormat, filePath) => {
+      ipcRenderer.send('universal-convert', { tool, fromFormat, toFormat, filePath });
+    },
+    convertBatch: (tool, fromFormat, toFormat, inputFolder, outputFolder) => {
+      ipcRenderer.send('universal-convert-batch', { tool, fromFormat, toFormat, inputFolder, outputFolder });
+    }
+  },
+
+  // Header/Footer Operations
+  headerFooter: {
+    getSettings: () => ipcRenderer.send('get-header-footer-settings'),
+    saveSettings: (settings) => ipcRenderer.send('save-header-footer-settings', settings),
+    browseLogo: (position) => ipcRenderer.send('browse-header-footer-logo', position),
+    saveLogo: (position, filePath) => ipcRenderer.send('save-header-footer-logo', { position, filePath }),
+    clearLogo: (position) => ipcRenderer.send('clear-header-footer-logo', position)
+  },
+
+  // Page Settings
+  page: {
+    getSettings: () => ipcRenderer.send('get-page-settings'),
+    updateSettings: (settings) => ipcRenderer.send('update-page-settings', settings),
+    setCustomStartPage: (pageNumber) => ipcRenderer.send('set-custom-start-page', pageNumber)
+  },
+
+  // PDF Operations
+  pdf: {
+    processOperation: (data) => ipcRenderer.send('process-pdf-operation', data),
+    getPageCount: (filePath) => ipcRenderer.send('get-pdf-page-count', filePath),
+    selectFolder: (inputId) => ipcRenderer.send('select-pdf-folder', inputId)
+  },
+
+  // Image Converter Operations
+  image: {
+    convert: (data) => ipcRenderer.send('image-convert', data),
+    batchConvert: (data) => ipcRenderer.send('image-batch-convert', data),
+    resize: (data) => ipcRenderer.send('image-resize', data),
+    compress: (data) => ipcRenderer.send('image-compress', data),
+    rotate: (data) => ipcRenderer.send('image-rotate', data)
+  },
+
+  // Audio Converter Operations
+  audio: {
+    convert: (data) => ipcRenderer.send('audio-convert', data),
+    batchConvert: (data) => ipcRenderer.send('audio-batch-convert', data),
+    extract: (data) => ipcRenderer.send('audio-extract', data),
+    trim: (data) => ipcRenderer.send('audio-trim', data),
+    merge: (data) => ipcRenderer.send('audio-merge', data)
+  },
+
+  // Video Converter Operations
+  video: {
+    convert: (data) => ipcRenderer.send('video-convert', data),
+    batchConvert: (data) => ipcRenderer.send('video-batch-convert', data),
+    compress: (data) => ipcRenderer.send('video-compress', data),
+    trim: (data) => ipcRenderer.send('video-trim', data),
+    extractFrames: (data) => ipcRenderer.send('video-frames', data),
+    toGif: (data) => ipcRenderer.send('video-gif', data)
+  },
+
+  // Generator Windows
+  generators: {
+    openAscii: () => ipcRenderer.send('open-ascii-generator'),
+    openTable: () => ipcRenderer.send('open-table-generator')
+  },
+
+  getAppVersion: () => ipcRenderer.invoke('get-app-version')
+});
+
+// Log successful preload initialization
+console.log('[Preload] Secure IPC bridge initialized');
+console.log('[Preload] Allowed send channels:', ALLOWED_SEND_CHANNELS.length);
+console.log('[Preload] Allowed receive channels:', ALLOWED_RECEIVE_CHANNELS.length);

src/print-preview.js

@@ -0,0 +1,138 @@
+class PrintPreview {
+    constructor() {
+        this.overlay = document.getElementById('print-preview-overlay');
+        this.modal = window.modals?.printPreviewModal;
+        this._lastContent = '';
+        this.setupEventListeners();
+    }
+
+    open(htmlContent) {
+        this._lastContent = htmlContent;
+        if (this.modal) {
+            this.modal.open();
+        } else {
+            this.overlay.classList.remove('hidden');
+        }
+        this.updatePreview(htmlContent);
+        this.updateScaleLabel();
+    }
+
+    close() {
+        if (this.modal) {
+            this.modal.close();
+        } else {
+            this.overlay.classList.add('hidden');
+        }
+    }
+
+    setupEventListeners() {
+        document.getElementById('print-preview-close')?.addEventListener('click', () => this.close());
+        document.getElementById('print-cancel')?.addEventListener('click', () => this.close());
+        document.getElementById('print-execute')?.addEventListener('click', () => this.executePrint());
+
+        // Update preview on option changes
+        ['print-paper-size', 'print-orientation', 'print-margins'].forEach(id => {
+            document.getElementById(id)?.addEventListener('change', () => this.refreshPreview());
+        });
+
+        // Scale slider
+        const scaleSlider = document.getElementById('print-scale');
+        scaleSlider?.addEventListener('input', () => this.updateScaleLabel());
+
+        // Page range toggle
+        document.getElementById('print-pages')?.addEventListener('change', (e) => {
+            const rangeInput = document.getElementById('print-page-range');
+            if (rangeInput) {
+                rangeInput.classList.toggle('hidden', e.target.value !== 'custom');
+            }
+        });
+
+        // Note: Backdrop click and Escape key are now handled by ModalManager
+    }
+
+    updateScaleLabel() {
+        const scale = document.getElementById('print-scale')?.value || 100;
+        const label = document.getElementById('print-scale-value');
+        if (label) label.textContent = `${scale}%`;
+    }
+
+    updatePreview(htmlContent) {
+        const frame = document.getElementById('print-preview-frame');
+        if (!frame) return;
+
+        this._lastContent = htmlContent;
+
+        const orientation = document.getElementById('print-orientation')?.value || 'portrait';
+        const paperSize = document.getElementById('print-paper-size')?.value || 'A4';
+
+        // Get dimensions for paper size
+        const sizes = {
+            'A3': { width: '297mm', height: '420mm' },
+            'A4': { width: '210mm', height: '297mm' },
+            'A5': { width: '148mm', height: '210mm' },
+            'Letter': { width: '8.5in', height: '11in' },
+            'Legal': { width: '8.5in', height: '14in' },
+            'Tabloid': { width: '11in', height: '17in' },
+        };
+
+        const size = sizes[paperSize] || sizes['A4'];
+        const width = orientation === 'landscape' ? size.height : size.width;
+        const height = orientation === 'landscape' ? size.width : size.height;
+
+        const previewHtml = `
+            <!DOCTYPE html>
+            <html>
+            <head>
+                <style>
+                    body {
+                        margin: 20px;
+                        font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
+                        font-size: 14px;
+                        line-height: 1.6;
+                    }
+                    @page { size: ${width} ${height}; }
+                    pre { background: #f5f5f5; padding: 12px; border-radius: 6px; overflow-x: auto; }
+                    code { background: #f0f0f0; padding: 2px 6px; border-radius: 3px; font-size: 13px; }
+                    pre code { background: none; padding: 0; }
+                    table { border-collapse: collapse; width: 100%; }
+                    th, td { border: 1px solid #ddd; padding: 8px; }
+                    blockquote { border-left: 4px solid #ddd; margin-left: 0; padding-left: 16px; color: #666; }
+                    img { max-width: 100%; }
+                    h1, h2, h3 { margin-top: 1.5em; }
+                </style>
+            </head>
+            <body>${htmlContent || ''}</body>
+            </html>
+        `;
+
+        frame.srcdoc = previewHtml;
+    }
+
+    refreshPreview() {
+        if (this._lastContent) {
+            this.updatePreview(this._lastContent);
+        }
+    }
+
+    getOptions() {
+        return {
+            paperSize: document.getElementById('print-paper-size')?.value || 'A4',
+            orientation: document.getElementById('print-orientation')?.value || 'portrait',
+            margins: document.getElementById('print-margins')?.value || 'default',
+            scale: parseInt(document.getElementById('print-scale')?.value || '100'),
+            headers: document.getElementById('print-headers')?.checked ?? true,
+            background: document.getElementById('print-background')?.checked ?? true,
+            pages: document.getElementById('print-pages')?.value || 'all',
+            pageRange: document.getElementById('print-page-range')?.value || '',
+        };
+    }
+
+    executePrint() {
+        const options = this.getOptions();
+        const { ipcRenderer } = require('electron');
+        ipcRenderer.send('do-print-with-options', options);
+        this.close();
+    }
+}
+
+module.exports = { PrintPreview };