chore(release): bump version to 4.4.3

This will help identify whether the issue is:
1. marked.parse returning a Promise instead of string
2. DOMPurify.sanitize failing
3. The preview element not existing
4. Libraries not being loaded

Amit Haridas

.github/workflows/release.yml

@@ -19,17 +19,17 @@ jobs:
           node-version: 20
           cache: npm
 
-      - name: Install rpmbuild
-        run: sudo apt-get update && sudo apt-get install -y rpm
-
       - 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
+        run: npm run build:linux-ci -- --publish=never
 
       - name: Upload Linux artifacts
         uses: actions/upload-artifact@v4
@@ -56,14 +56,19 @@ jobs:
       - 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: ${{ secrets.CSC_LINK_BASE64 != '' }}
+        if: ${{ env.CSC_LINK_BASE64 != '' }}
         shell: pwsh
+        env:
+          CSC_LINK_BASE64: ${{ secrets.CSC_LINK_BASE64 }}
         run: |
-          $bytes = [Convert]::FromBase64String("${{ secrets.CSC_LINK_BASE64 }}")
+          $bytes = [Convert]::FromBase64String("$env:CSC_LINK_BASE64")
           [IO.File]::WriteAllBytes("${{ github.workspace }}\code-signing-cert.pfx", $bytes)
           echo "CERT_AVAILABLE=true" >> $env:GITHUB_ENV
 
@@ -72,13 +77,13 @@ jobs:
         env:
           CSC_LINK: code-signing-cert.pfx
           CSC_KEY_PASSWORD: ${{ secrets.CSC_KEY_PASSWORD }}
-        run: npm run build:win-signed
+        run: npm run build:win-signed -- --publish=never
 
       - name: Build Windows packages (unsigned)
         if: ${{ env.CERT_AVAILABLE != 'true' }}
         env:
-          CSC_IDENTITY_AUTO_DISCOVERY: false
+          CSC_IDENTITY_AUTO_DISCOVERY: 'false'
-        run: npm run build:win-unsigned
+        run: npm run build:win-unsigned -- --publish=never
 
       - name: Upload Windows artifacts
         uses: actions/upload-artifact@v4
@@ -86,24 +91,26 @@ jobs:
           name: windows-artifacts
           path: |
             dist/*.exe
-            dist/*-win.zip
             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

.gitignore

@@ -16,7 +16,10 @@ 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
@@ -40,3 +43,6 @@ pdf\ modal.png
 CLAUDE.md
 agents.md
 coverage/
+
+# Superpowers brainstorm artifacts
+.superpowers/

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

@@ -75,6 +75,7 @@ module.exports = [
         jest: 'readonly',
         describe: 'readonly',
         test: 'readonly',
+        it: 'readonly',
         expect: 'readonly',
         beforeEach: 'readonly',
         afterEach: 'readonly',

package.json

@@ -1,6 +1,6 @@
 {
   "name": "markdown-converter",
-  "version": "4.3.0",
+  "version": "4.4.3",
   "description": "Professional Markdown editor and universal file converter with PDF editing, batch processing, and syntax highlighting",
   "main": "src/main.js",
   "scripts": {
@@ -19,9 +19,11 @@
     "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": [
@@ -71,9 +73,10 @@
     "codemirror": "^6.0.2",
     "core-util-is": "^1.0.3",
     "docx": "^9.6.0",
-    "docx4js": "^3.3.0",
+    "docx4js": "^2.0.1",
     "dompurify": "^3.3.1",
     "electron-store": "^10.1.0",
+    "ffmpeg-static": "^5.3.0",
     "highlight.js": "^11.11.1",
     "html2pdf.js": "^0.14.0",
     "marked": "^17.0.3",
@@ -109,6 +112,10 @@
       "node_modules/**/*",
       "package.json"
     ],
+    "asarUnpack": [
+      "node_modules/ffmpeg-static/**"
+    ],
+    "extraFiles": [],
     "fileAssociations": [
       {
         "ext": "md",
@@ -160,7 +167,14 @@
       "artifactName": "${productName}-${version}-${arch}.${ext}",
       "requestedExecutionLevel": "asInvoker",
       "legalTrademarks": "Copyright (C) 2024-2025 ConcreteInfo",
-      "verifyUpdateCodeSignature": false
+      "verifyUpdateCodeSignature": false,
+      "signAndEditExecutable": false,
+      "extraFiles": [
+        {
+          "from": "bin/win32/pandoc.exe",
+          "to": "bin/pandoc.exe"
+        }
+      ]
     },
     "nsis": {
       "oneClick": false,
@@ -182,29 +196,24 @@
       "target": [
         "deb",
         "AppImage",
-        "snap",
+        "snap"
-        "rpm"
       ],
       "category": "Utility",
-      "maintainer": "ConcreteInfo <amit.wh@gmail.com>"
+      "maintainer": "ConcreteInfo <amit.wh@gmail.com>",
+      "extraFiles": [
+        {
+          "from": "bin/linux/pandoc",
+          "to": "bin/pandoc"
+        }
+      ]
     },
     "deb": {
       "depends": [
-        "pandoc",
-        "ffmpeg",
         "imagemagick",
         "libreoffice-common"
       ],
       "description": "Professional Markdown editor and universal file converter",
       "maintainer": "ConcreteInfo <amit.wh@gmail.com>"
-    },
-    "rpm": {
-      "depends": [
-        "pandoc",
-        "ffmpeg",
-        "ImageMagick",
-        "libreoffice-core"
-      ]
     }
   }
 }

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);
+});

src/adapters/electron/fs.js

@@ -4,7 +4,7 @@
  * Implements file system operations for Electron using IPC.
  * This abstracts file operations to enable easier testing and migration.
  *
- * @version 4.1.0
+ * @version 4.4.1
  */
 
 /**

src/adapters/types.js

@@ -5,7 +5,7 @@
  * Adapters abstract file system, conversion, and system operations
  * to enable easier testing and future platform migration.
  *
- * @version 4.1.0
+ * @version 4.4.1
  */
 
 /**

src/editor/codemirror-setup.js

@@ -59,6 +59,11 @@ const jetBrainsMonoTheme = EditorView.theme({
  * @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 = () => {},

src/index.html

@@ -31,7 +31,7 @@
                 <span class="app-title">MarkdownConverter</span>
             </div>
             <div class="app-header-right">
-                <span class="app-version">v4.2.0</span>
+                <span class="app-version" id="app-version-display"></span>
             </div>
         </div>
         <div class="tab-bar" id="tab-bar" role="tablist" aria-label="Document tabs">
@@ -288,6 +288,52 @@
                         </div>
                     </div>
 
+                    <div class="export-section revealjs-only" style="display: none;">
+                        <label>Reveal.js Options:</label>
+                        <div class="form-row">
+                            <label for="reveal-theme">Slide Theme:</label>
+                            <select id="reveal-theme">
+                                <option value="black">Black</option>
+                                <option value="white">White</option>
+                                <option value="league">League</option>
+                                <option value="beige">Beige</option>
+                                <option value="sky">Sky</option>
+                                <option value="night">Night</option>
+                                <option value="serif">Serif</option>
+                                <option value="simple">Simple</option>
+                                <option value="solarized">Solarized</option>
+                                <option value="blood">Blood</option>
+                                <option value="moon">Moon</option>
+                            </select>
+                        </div>
+                        <div class="form-row">
+                            <label for="reveal-transition">Transition:</label>
+                            <select id="reveal-transition">
+                                <option value="slide">Slide</option>
+                                <option value="none">None</option>
+                                <option value="fade">Fade</option>
+                                <option value="convex">Convex</option>
+                                <option value="concave">Concave</option>
+                                <option value="zoom">Zoom</option>
+                            </select>
+                        </div>
+                        <div class="form-row">
+                            <label for="reveal-speed">Transition Speed:</label>
+                            <select id="reveal-speed">
+                                <option value="default">Default</option>
+                                <option value="fast">Fast</option>
+                                <option value="slow">Slow</option>
+                            </select>
+                        </div>
+                        <div class="checkbox-group">
+                            <label><input type="checkbox" id="reveal-slide-number"> Slide Numbers</label>
+                            <label><input type="checkbox" id="reveal-controls" checked> Controls</label>
+                            <label><input type="checkbox" id="reveal-progress" checked> Progress Bar</label>
+                            <label><input type="checkbox" id="reveal-history" checked> Slide History</label>
+                            <label><input type="checkbox" id="reveal-center" checked> Center Content</label>
+                        </div>
+                    </div>
+
                     <div class="export-section">
                         <label>Bibliography:</label>
                         <div class="form-row">
@@ -905,6 +951,7 @@
                     <button class="modal-close" id="pdf-editor-dialog-close" aria-label="Close">&times;</button>
                 </div>
                 <div class="modal-body pdf-editor-body">
+                    <div class="pdf-editor-left-panel">
                     <!-- Merge PDFs Section -->
                     <div id="pdf-merge-section" class="pdf-operation-section hidden">
                         <div class="export-section">
@@ -1287,6 +1334,16 @@
                         </div>
                     </div>
                 </div>
+
+                <!-- Right Panel: Scrollable Visual Page Sidebar -->
+                <div id="pdf-thumbnail-sidebar" class="pdf-editor-right-panel hidden">
+                    <h4>Page Preview &amp; Editor</h4>
+                    <p class="sidebar-help">Select a PDF to view pages, check to delete, click ↻ to rotate, and use ◀ / ▶ to reorder.</p>
+                    <div id="pdf-thumbnail-grid" class="pdf-thumbnail-grid">
+                        <!-- Page thumbnail cards will be rendered here dynamically -->
+                    </div>
+                </div>
+            </div>
                 <div class="modal-footer">
                     <button id="pdf-editor-cancel" class="btn btn-secondary" data-close>Cancel</button>
                     <button id="pdf-editor-process" class="btn btn-primary">Process</button>

src/main.js

@@ -2,8 +2,9 @@ const { app, BrowserWindow, Menu, dialog, ipcMain, shell } = require('electron')
 const path = require('path');
 const fs = require('fs');
 const { exec, execFile, spawn } = require('child_process');
-const { PDFDocument, rgb, degrees, StandardFonts } = require('pdf-lib');
 const WordTemplateExporter = require('./wordTemplateExporter');
+const PDFOperations = require('./main/PDFOperations');
+const GitOperations = require('./main/GitOperations');
 
 // Add MiKTeX to PATH for LaTeX support
 if (process.platform === 'win32') {
@@ -14,13 +15,39 @@ if (process.platform === 'win32') {
   }
 }
 
-// Get the system Pandoc path
+// Returns path to pandoc: bundled binary when packaged, dev bin or system fallback otherwise.
 function getPandocPath() {
-  // Pandoc is expected to be in the system's PATH.
+  if (app.isPackaged) {
-  // The command will be executed directly. Quoting is handled by exec.
+    const ext = process.platform === 'win32' ? '.exe' : '';
+    return path.join(process.resourcesPath, 'bin', `pandoc${ext}`);
+  }
+  // Development: prefer locally-downloaded binary in bin/<platform>/
+  const devBin = path.join(
+    __dirname,
+    '..',
+    'bin',
+    process.platform,
+    process.platform === 'win32' ? 'pandoc.exe' : 'pandoc',
+  );
+  if (fs.existsSync(devBin)) return devBin;
   return 'pandoc';
 }
 
+// Returns path to ffmpeg: asar-unpacked bundled binary when packaged, system fallback otherwise.
+function getFFmpegPath() {
+  try {
+    let ffmpegPath = require('ffmpeg-static');
+    if (app.isPackaged) {
+      // ffmpeg-static is in asarUnpack — rewrite the path to the unpacked location
+      ffmpegPath = ffmpegPath.replace('app.asar' + path.sep, 'app.asar.unpacked' + path.sep);
+    }
+    if (fs.existsSync(ffmpegPath)) return ffmpegPath;
+  } catch (_) {
+    /* ffmpeg-static not available */
+  }
+  return process.platform === 'win32' ? 'ffmpeg' : 'ffmpeg';
+}
+
 // Check if Pandoc is available
 function checkPandocAvailable() {
   return new Promise((resolve) => {
@@ -283,6 +310,41 @@ const store = {
   }
 };
 
+// Plugin settings IPC handlers
+ipcMain.handle('plugin-settings:get', (_event, key) => {
+  return store.get(key);
+});
+ipcMain.handle('plugin-settings:set', (_event, { key, value }) => {
+  store.set(key, value);
+});
+ipcMain.handle('get-app-version', () => app.getVersion());
+
+// ============================================
+// SECURITY: Permission Request Handler
+// ============================================
+// Restrict permissions to only those explicitly needed.
+// Deny: camera, microphone, geolocation, notifications, etc.
+// Allow: clipboard-read, clipboard-write (user expects these)
+app.on('web-contents-created', (event, contents) => {
+  contents.session.setPermissionRequestHandler((webContents, permission, callback) => {
+    const ALLOWED_PERMISSIONS = [
+      'clipboard-read',
+      'clipboard-write'
+    ];
+
+    if (ALLOWED_PERMISSIONS.includes(permission)) {
+      callback(true);
+    } else {
+      // Deny all other permissions (camera, microphone, geolocation, etc.)
+      console.warn(`[Security] Blocked permission request: ${permission}`);
+      callback(false);
+    }
+  });
+
+  // Disable file download dialogs for security
+  // contents.session.setDownloadPath(userDownloadsPath);
+});
+
 let mainWindow;
 let currentFile = null; // This will now represent the active tab's file
 let pandocAvailable = null; // Cache pandoc availability check
@@ -787,6 +849,20 @@ function createMenu() {
           }
         },
         { type: 'separator' },
+        {
+          label: 'Custom Preview CSS',
+          submenu: [
+            {
+              label: 'Load Custom Preview CSS...',
+              click: () => mainWindow.webContents.send('load-custom-css')
+            },
+            {
+              label: 'Clear Custom Preview CSS',
+              click: () => mainWindow.webContents.send('clear-custom-css')
+            }
+          ]
+        },
+        { type: 'separator' },
         { label: 'Reload', accelerator: 'CmdOrCtrl+R', role: 'reload' },
         { label: 'Toggle DevTools', accelerator: 'F12', role: 'toggleDevTools' },
         { type: 'separator' },
@@ -1029,7 +1105,7 @@ function showAboutDialog() {
 <body>
   <img src="${iconBase64}" class="logo" alt="MarkdownConverter">
   <h1>MarkdownConverter</h1>
-  <div class="version">Version 4.1.0</div>
+  <div class="version">Version ${app.getVersion()}</div>
 
   <div class="company">
     <span>by</span>
@@ -1833,9 +1909,12 @@ function checkConverterAvailable(tool) {
       case 'imagemagick':
         toolName = isWin ? 'magick' : 'convert';
         break;
-      case 'ffmpeg':
+      case 'ffmpeg': {
-        toolName = 'ffmpeg';
+        // ffmpeg-static is always bundled — check it directly
-        break;
+        const ffmpegBin = getFFmpegPath();
+        resolve(fs.existsSync(ffmpegBin) || ffmpegBin === 'ffmpeg');
+        return;
+      }
       default:
         resolve(false);
         return;
@@ -2062,8 +2141,8 @@ function convertWithImageMagick(inputFile, outputPath) {
 // FFmpeg conversion - returns {command, args} for execFile
 function convertWithFFmpeg(inputFile, outputPath) {
   return {
-    command: 'ffmpeg',
+    command: getFFmpegPath(),
-    args: ['-i', inputFile, outputPath, '-y']
+    args: ['-i', inputFile, outputPath, '-y'],
   };
 }
 
@@ -2232,8 +2311,32 @@ function performExportWithOptions(format, options) {
         dialog.showErrorBox('Export Error', sanitizeErrorMessage(`Failed to export: ${err.message}`));
       }
     } else if (format === 'revealjs') {
-      pandocCmd = `${getPandocPath()} "${currentFile}" -t revealjs -s -o "${outputFile}" --slide-level=2`;
+      let revealCmd = `${getPandocPath()} "${currentFile}" -t revealjs -s -o "${outputFile}" --slide-level=2`;
-      exportWithPandoc(pandocCmd, outputFile, format);
+      if (options) {
+        if (options.revealTheme) revealCmd += ` -V theme="${options.revealTheme}"`;
+        if (options.revealTransition) revealCmd += ` -V transition="${options.revealTransition}"`;
+        if (options.revealTransitionSpeed) revealCmd += ` -V transitionSpeed="${options.revealTransitionSpeed}"`;
+        if (options.revealControls !== undefined) revealCmd += ` -V controls="${options.revealControls}"`;
+        if (options.revealSlideNumber !== undefined) revealCmd += ` -V slideNumber="${options.revealSlideNumber}"`;
+        if (options.revealProgress !== undefined) revealCmd += ` -V progress="${options.revealProgress}"`;
+        if (options.revealHistory !== undefined) revealCmd += ` -V history="${options.revealHistory}"`;
+        if (options.revealCenter !== undefined) revealCmd += ` -V center="${options.revealCenter}"`;
+
+        // Support for templates, metadata, bibliography
+        if (options.template && options.template !== 'default') {
+          revealCmd += ` --template="${options.template}"`;
+        }
+        if (options.metadata) {
+          for (const [key, value] of Object.entries(options.metadata)) {
+            if (value.trim()) {
+              revealCmd += ` -M ${key}="${value.replace(/"/g, '\\"')}"`;
+            }
+          }
+        }
+        if (options.bibliography) revealCmd += ` --bibliography="${options.bibliography}"`;
+        if (options.csl) revealCmd += ` --csl="${options.csl}"`;
+      }
+      exportWithPandoc(revealCmd, outputFile, format);
     } else if (format === 'beamer') {
       pandocCmd = `${getPandocPath()} "${currentFile}" -t beamer -o "${outputFile}"`;
       exportWithPandoc(pandocCmd, outputFile, format);
@@ -3694,7 +3797,7 @@ app.on('open-file', (event, filePath) => {
 // Handle file opening from command line or file association
 function openFileFromPath(filePath) {
   console.log('[MAIN] openFileFromPath called with:', filePath);
-  console.log('[MAIN] rendererReady:', rendererReady, 'mainWindow exists:', !!mainWindow);
+  console.log('[MAIN] rendererReady:', rendererReady, 'mainWindow exists:', !!mainWindow, 'webContents exists:', !!(mainWindow?.webContents));
   if (fs.existsSync(filePath)) {
     const stats = fs.statSync(filePath);
     if (stats.size > MAX_FILE_SIZE) {
@@ -3704,6 +3807,7 @@ function openFileFromPath(filePath) {
     currentFile = filePath;
     const content = fs.readFileSync(filePath, 'utf-8');
     console.log('[MAIN] File read successfully, content length:', content.length);
+    console.log('[MAIN] About to send file-opened. mainWindow:', !!mainWindow, 'webContents:', !!(mainWindow?.webContents), 'rendererReady:', rendererReady);
     if (mainWindow && mainWindow.webContents && rendererReady) {
       // Send file immediately - renderer-ready means UI is initialized
       console.log('[MAIN] Sending file-opened to renderer');
@@ -3719,433 +3823,9 @@ function openFileFromPath(filePath) {
 }
 
 // ========================================
-// PDF EDITOR OPERATIONS (using pdf-lib)
+// PDF OPERATIONS — delegates to main/PDFOperations.js
 // ========================================
 
-// Helper function to parse page ranges (e.g., "1-5, 7, 9-12")
-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)) { // Convert to 0-indexed
-          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);
-}
-
-// Helper function to convert hex color to RGB
-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 };
-}
-
-// PDF Merge Operation
-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 ${data.inputFiles.length} PDFs` };
-  } catch (error) {
-    return { success: false, error: error.message };
-  }
-}
-
-// PDF Split Operation
-async function pdfSplit(data) {
-  try {
-    const pdfBytes = fs.readFileSync(data.inputPath);
-    const pdf = await PDFDocument.load(pdfBytes);
-    const totalPages = pdf.getPageCount();
-
-    let splits = [];
-
-    if (data.splitMode === 'pages') {
-      // Split by page ranges
-      const ranges = data.pageRanges.split(',').map(r => r.trim());
-      for (let i = 0; i < ranges.length; i++) {
-        const range = ranges[i];
-        let pages = [];
-
-        if (range.includes('-')) {
-          const [start, end] = range.split('-').map(n => parseInt(n.trim()));
-          for (let p = start; p <= end && p <= totalPages; p++) {
-            pages.push(p - 1);
-          }
-        } else {
-          const page = parseInt(range);
-          if (page > 0 && page <= totalPages) {
-            pages.push(page - 1);
-          }
-        }
-
-        if (pages.length > 0) {
-          splits.push({ pages, name: `part_${i + 1}` });
-        }
-      }
-    } else if (data.splitMode === 'interval') {
-      // Split every N pages
-      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_${Math.floor(i / interval) + 1}` });
-      }
-    } else if (data.splitMode === 'size') {
-      // Split by size (approximate - we'll split evenly)
-      // This is complex, so we'll do a simple even split for now
-      const maxSize = data.maxSize * 1024 * 1024; // Convert MB to bytes
-      // For simplicity, split into fixed page chunks
-      const chunkSize = Math.max(1, Math.floor(totalPages / 5)); // Split into ~5 parts
-      for (let i = 0; i < totalPages; i += chunkSize) {
-        const pages = [];
-        for (let j = i; j < i + chunkSize && j < totalPages; j++) {
-          pages.push(j);
-        }
-        splits.push({ pages, name: `part_${Math.floor(i / chunkSize) + 1}` });
-      }
-    }
-
-    // Create split PDFs
-    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 };
-  }
-}
-
-// PDF Compress Operation
-async function pdfCompress(data) {
-  try {
-    const pdfBytes = fs.readFileSync(data.inputPath);
-    const pdf = await PDFDocument.load(pdfBytes);
-
-    // pdf-lib doesn't have built-in compression, but we can save with default compression
-    // For actual compression, we would need additional libraries like Ghostscript
-    // For now, we'll save with standard options which provides some compression
-    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 };
-  }
-}
-
-// PDF Rotate Pages Operation
-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 {
-      // Rotate all pages
-      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}°`
-    };
-  } catch (error) {
-    return { success: false, error: error.message };
-  }
-}
-
-// PDF Delete Pages Operation
-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);
-
-    // Remove pages in reverse order to maintain indices
-    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 };
-  }
-}
-
-// PDF Reorder Pages Operation
-async function pdfReorder(data) {
-  try {
-    const pdfBytes = fs.readFileSync(data.inputPath);
-    const pdf = await PDFDocument.load(pdfBytes);
-    const totalPages = pdf.getPageCount();
-
-    // Parse new page order
-    const newOrder = data.newOrder.split(',').map(n => parseInt(n.trim()) - 1); // Convert to 0-indexed
-
-    // Validate new order
-    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 };
-  }
-}
-
-// PDF Watermark Operation
-async function pdfWatermark(data) {
-  try {
-    const pdfBytes = fs.readFileSync(data.inputPath);
-    const pdf = await PDFDocument.load(pdfBytes);
-    const totalPages = pdf.getPageCount();
-
-    // Determine which pages to watermark
-    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;
-
-      // Calculate position based on selected position
-      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 };
-  }
-}
-
-// PDF Encrypt (Password Protection) Operation
-async function pdfEncrypt(data) {
-  try {
-    const pdfBytes = fs.readFileSync(data.inputPath);
-    const pdf = await PDFDocument.load(pdfBytes);
-
-    // pdf-lib has limited encryption support in v1.17.1
-    // We'll save with password (basic encryption)
-    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 pdf-lib doesn't support encryption in this version, provide a helpful 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 };
-  }
-}
-
-// PDF Decrypt (Remove Password) Operation
-async function pdfDecrypt(data) {
-  try {
-    const pdfBytes = fs.readFileSync(data.inputPath);
-    const pdf = await PDFDocument.load(pdfBytes, { password: data.password });
-
-    // Save without 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 };
-  }
-}
-
-// PDF Permissions Operation
-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 };
-  }
-}
-
-// IPC Handler for PDF Operations
 ipcMain.on('process-pdf-operation', async (event, data) => {
   try {
     mainWindow.webContents.send('pdf-operation-progress', {
@@ -4153,43 +3833,7 @@ ipcMain.on('process-pdf-operation', async (event, data) => {
       progress: 10
     });
 
-    let result;
+    const result = await PDFOperations.executeOperation(data.operation, data);
-
-    switch (data.operation) {
-      case 'merge':
-        result = await pdfMerge(data);
-        break;
-      case 'split':
-        result = await pdfSplit(data);
-        break;
-      case 'compress':
-        result = await pdfCompress(data);
-        break;
-      case 'rotate':
-        result = await pdfRotate(data);
-        break;
-      case 'delete':
-        result = await pdfDeletePages(data);
-        break;
-      case 'reorder':
-        result = await pdfReorder(data);
-        break;
-      case 'watermark':
-        result = await pdfWatermark(data);
-        break;
-      case 'encrypt':
-        result = await pdfEncrypt(data);
-        break;
-      case 'decrypt':
-        result = await pdfDecrypt(data);
-        break;
-      case 'permissions':
-        result = await pdfSetPermissions(data);
-        break;
-      default:
-        result = { success: false, error: `Unknown operation: ${data.operation}` };
-    }
-
     mainWindow.webContents.send('pdf-operation-complete', result);
   } catch (error) {
     mainWindow.webContents.send('pdf-operation-complete', {
@@ -4199,12 +3843,9 @@ ipcMain.on('process-pdf-operation', async (event, data) => {
   }
 });
 
-// IPC Handler for getting PDF page count
 ipcMain.on('get-pdf-page-count', async (event, filePath) => {
   try {
-    const pdfBytes = fs.readFileSync(filePath);
+    const count = await PDFOperations.getPageCount(filePath);
-    const pdf = await PDFDocument.load(pdfBytes);
-    const count = pdf.getPageCount();
     event.reply('pdf-page-count', { count });
   } catch (error) {
     event.reply('pdf-page-count', { error: error.message });
@@ -4388,6 +4029,25 @@ ipcMain.handle('list-directory', async (event, dirPath) => {
   }
 });
 
+ipcMain.handle('select-custom-css', async (event) => {
+  const result = dialog.showOpenDialogSync(mainWindow, {
+    title: 'Select Custom Preview CSS',
+    properties: ['openFile'],
+    filters: [
+      { name: 'CSS Stylesheets', extensions: ['css'] }
+    ]
+  });
+
+  if (result && result[0]) {
+    const filePath = result[0];
+    const content = fs.readFileSync(filePath, 'utf-8');
+    return { path: filePath, content };
+  }
+  return null;
+});
+
+
+
 ipcMain.handle('read-file', async (event, filePath) => {
   const validation = validatePath(filePath);
   if (!validation.valid || !isPathAccessible(validation.resolved)) {
@@ -4512,49 +4172,24 @@ ipcMain.on('open-file-path', (event, filePath) => {
 // ============================================
 // Git IPC Handlers
 // ============================================
-const simpleGit = require('simple-git');
-
-function getGitRepo() {
-  // Use the directory of the current file, or the app's working directory
-  const dir = currentFile ? path.dirname(currentFile) : process.cwd();
-  return simpleGit(dir);
-}
-
 ipcMain.handle('git-status', async () => {
-  try {
+  const dir = currentFile ? path.dirname(currentFile) : process.cwd();
-    const git = getGitRepo();
+  return GitOperations.getStatus(dir);
-    return await git.status();
-  } catch (err) {
-    return { error: 'Not a git repository' };
-  }
 });
 
 ipcMain.handle('git-stage', async (event, { files }) => {
-  try {
+  const dir = currentFile ? path.dirname(currentFile) : process.cwd();
-    const git = getGitRepo();
+  return GitOperations.stage(dir, files);
-    await git.add(files);
-    return await git.status();
-  } catch (err) {
-    return { error: err.message };
-  }
 });
 
 ipcMain.handle('git-commit', async (event, { message }) => {
-  try {
+  const dir = currentFile ? path.dirname(currentFile) : process.cwd();
-    const git = getGitRepo();
+  return GitOperations.commit(dir, message);
-    return await git.commit(message);
-  } catch (err) {
-    return { error: err.message };
-  }
 });
 
 ipcMain.handle('git-log', async () => {
-  try {
+  const dir = currentFile ? path.dirname(currentFile) : process.cwd();
-    const git = getGitRepo();
+  return GitOperations.log(dir);
-    return await git.log({ maxCount: 20 });
-  } catch (err) {
-    return { error: err.message };
-  }
 });
 
 // ============================================

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

@@ -9,7 +9,7 @@
  * - All IPC channels are explicitly whitelisted
  * - Prevents XSS from escalating to full system access
  *
- * @version 4.1.0
+ * @version 4.4.1
  */
 
 const { contextBridge, ipcRenderer } = require('electron');
@@ -23,6 +23,7 @@ const ALLOWED_SEND_CHANNELS = [
   'save-recent-files',
   'clear-recent-files',
   'renderer-ready',
+  'select-custom-css',
 
   // Theme
   'get-theme',
@@ -135,7 +136,11 @@ const ALLOWED_SEND_CHANNELS = [
   'export',
 
   // Git diff
-  'git-diff'
+  'git-diff',
+
+  // Plugin settings
+  'plugin-settings:get',
+  'plugin-settings:set'
 ];
 
 const ALLOWED_RECEIVE_CHANNELS = [
@@ -146,6 +151,8 @@ const ALLOWED_RECEIVE_CHANNELS = [
   'get-content-for-save',
   'get-content-for-spreadsheet',
   'recent-files-cleared',
+  'load-custom-css',
+  'clear-custom-css',
 
   // UI toggles
   'toggle-preview',
@@ -429,7 +436,9 @@ contextBridge.exposeInMainWorld('electronAPI', {
   generators: {
     openAscii: () => ipcRenderer.send('open-ascii-generator'),
     openTable: () => ipcRenderer.send('open-table-generator')
-  }
+  },
+
+  getAppVersion: () => ipcRenderer.invoke('get-app-version')
 });
 
 // Log successful preload initialization

src/renderer.js

@@ -1,16 +1,64 @@
 /**
  * MarkdownConverter Renderer Process
- * @version 4.1.0
+ * @version 4.4.3
  */
 
 const { ipcRenderer } = require('electron');
 const marked = require('marked');
 const { markedHighlight } = require('marked-highlight');
-const DOMPurify = require('dompurify');
+const createDOMPurify = require('dompurify');
+const DOMPurify = createDOMPurify(window);
 const hljs = require('highlight.js');
 const { createEditor } = require('./editor/codemirror-setup');
 const { undo, redo } = require('@codemirror/commands');
-const { ModalManager } = require('./utils/ModalManager');
+
+// Define a fallback window.electronAPI object for when contextIsolation is disabled
+// and the preload script is not loaded in the main window context.
+if (typeof window !== 'undefined' && !window.electronAPI) {
+    window.electronAPI = {
+        send: (channel, data) => {
+            ipcRenderer.send(channel, data);
+        },
+        invoke: async (channel, data) => {
+            return await ipcRenderer.invoke(channel, data);
+        },
+        on: (channel, callback) => {
+            const subscription = (event, ...args) => callback(...args);
+            ipcRenderer.on(channel, subscription);
+            return () => {
+                ipcRenderer.removeListener(channel, subscription);
+            };
+        },
+        once: (channel, callback) => {
+            ipcRenderer.once(channel, (event, ...args) => callback(...args));
+        },
+        removeAllListeners: (channel) => {
+            ipcRenderer.removeAllListeners(channel);
+        },
+        getAppVersion: () => ipcRenderer.invoke('get-app-version'),
+        file: {
+            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 })
+        }
+    };
+}
+
+// Use window.ModalManager if already set by script tag, otherwise require it.
+// This prevents "Identifier 'ModalManager' has already been declared" when
+// both the script tag in index.html and CommonJS require() declare it.
+let _ModalManager;
+if (typeof window !== 'undefined' && window.ModalManager) {
+    _ModalManager = window.ModalManager;
+} else {
+    const result = require('./utils/ModalManager');
+    _ModalManager = result.ModalManager || result;
+}
 // Lazy-loaded modules — defer heavy imports until first use
 let _SidebarManager, _renderTemplatesPanel, _renderExplorerPanel, _renderGitPanel, _renderSnippetsPanel;
 let _ReplPanel, _CommandPalette, _PrintPreview, _createWelcomeContent;
@@ -101,19 +149,24 @@ marked.use({
         start(src) { return src.match(/^:::(note|warning|tip|danger|info)/m)?.index; },
         tokenizer(src) {
             const match = src.match(/^:::(note|warning|tip|danger|info)\s*\n([\s\S]*?)^:::\s*$/m);
-            if (match) {
+            if (match && match.index === 0) {
+                const admonitionType = match[1];
+                const text = match[2].trim();
+                const tokens = [];
+                this.lexer.blockTokens(text, tokens);
                 return {
                     type: 'admonition',
                     raw: match[0],
-                    admonitionType: match[1],
+                    admonitionType,
-                    text: match[2].trim()
+                    text,
+                    tokens
                 };
             }
         },
         renderer(token) {
             const icons = { note: '\u2139', warning: '\u26A0', tip: '\uD83D\uDCA1', danger: '\uD83D\uDD34', info: '\u2139' };
             const icon = icons[token.admonitionType] || '\u2139';
-            const inner = this.parser.parse(token.text);
+            const inner = this.parser.parse(token.tokens || []);
             return `<div class="admonition admonition-${token.admonitionType}">
                 <div class="admonition-title">${icon} ${token.admonitionType.charAt(0).toUpperCase() + token.admonitionType.slice(1)}</div>
                 <div class="admonition-content">${inner}</div>
@@ -130,6 +183,21 @@ function plantumlEncode(text) {
     return '~h' + hex;
 }
 
+// Scopes user custom CSS by prefixing all selectors to protect application UI
+function scopeCSS(cssText, scopeSelector) {
+    if (!cssText) return '';
+    return cssText.replace(/([^\r\n,{}]+)(,(?=[^}]*{)|(?=[^{]*{))/g, (match, selector, separator) => {
+        const trimmed = selector.trim();
+        if (!trimmed || trimmed.startsWith('@') || trimmed.startsWith(':root') || trimmed.startsWith('from') || trimmed.startsWith('to') || /^\d+%$/.test(trimmed)) {
+            return match;
+        }
+        return scopeSelector + ' ' + trimmed + (separator || '');
+    });
+}
+
+// Module-level reference set by DOMContentLoaded after sidebar registration
+const outlinePanelContainer = null;
+
 // Tab Management
 class TabManager {
     constructor() {
@@ -143,6 +211,7 @@ class TabManager {
         this.recentFiles = JSON.parse(localStorage.getItem('recentFiles') || '[]');
         this.previewDebounceTimers = new Map(); // Debounce timers per tab
         this.previewDebounceDelay = 300; // 300ms debounce
+        this.previewCache = new Map(); // Performance optimization render cache
 
         // Initialize first tab
         this.tabs.set(1, {
@@ -226,7 +295,7 @@ class TabManager {
             editorView: null,
             findMatches: [],
             currentMatchIndex: -1,
-            type: type,
+            type: type, // 'markdown' or 'pdf'
             // PDF-specific state
             pdfDoc: null,
             pdfCurrentPage: 1,
@@ -239,6 +308,7 @@ class TabManager {
         this.switchToTab(newTabId);
         this.startAutoSave();
         this.updateTabBar();
+        console.log('createNewTab: tab created with type:', type);
     }
 
     createPdfTab(filePath) {
@@ -458,6 +528,17 @@ class TabManager {
                 onChange: (newContent) => {
                     tab.content = newContent;
                     tab.isDirty = true;
+                    // Dynamically enable/disable Large File Mode on edit
+                    if (newContent.length > 1024 * 1024) {
+                        if (!tab.largeFileMode) {
+                            tab.largeFileMode = true;
+                            this.isPreviewVisible = false;
+                            this.updatePreviewVisibility();
+                            notifyUser('Large content detected (>1MB). Large File Mode enabled to maintain peak responsiveness. Live preview auto-render is disabled.', 'warning');
+                        }
+                    } else {
+                        tab.largeFileMode = false;
+                    }
                     this.updatePreview(tab.id);
                     this.updateWordCount();
                     this.updateTabBar();
@@ -656,6 +737,11 @@ class TabManager {
         const tab = this.tabs.get(tabId);
         if (!tab || tab.type === 'pdf') return;
 
+        // Guard against auto-renders in large file mode
+        if (tab.largeFileMode && !immediate) {
+            return;
+        }
+
         // Clear existing debounce timer for this tab
         if (this.previewDebounceTimers.has(tabId)) {
             clearTimeout(this.previewDebounceTimers.get(tabId));
@@ -674,20 +760,55 @@ class TabManager {
         }, this.previewDebounceDelay));
     }
 
+    _hash(str) {
+        if (!str) return 0;
+        let hash = 0;
+        for (let i = 0; i < str.length; i++) {
+            hash = ((hash << 5) - hash) + str.charCodeAt(i);
+            hash |= 0; // Convert to 32bit integer
+        }
+        return hash;
+    }
+
     _renderPreview(tabId) {
         const tab = this.tabs.get(tabId);
         const preview = document.getElementById(`preview-${tabId}`);
+        console.log('[_renderPreview] tabId:', tabId, 'tab exists:', !!tab, 'preview exists:', !!preview, 'content length:', tab?.content?.length);
 
         if (!tab || !preview) return;
 
         try {
             // Check if libraries are available
             if (!marked || !DOMPurify) {
+                console.error('[_renderPreview] Libraries not available:', { marked: !!marked, DOMPurify: !!DOMPurify });
                 preview.innerHTML = '<div class="preview-error"><div class="preview-error-icon">⚠️</div><div class="preview-error-title">Libraries Not Loaded</div><div class="preview-error-message">Required libraries (marked/DOMPurify) could not be loaded. Please check your installation.</div></div>';
                 return;
             }
+
+            // Cache lookup
+            const contentHash = this._hash(tab.content);
+            let sanitizedHtml;
+            if (this.previewCache.has(contentHash)) {
+                console.log('[_renderPreview] Cache hit for hash:', contentHash);
+                sanitizedHtml = this.previewCache.get(contentHash);
+            } else {
+                console.log('[_renderPreview] Cache miss. About to call marked.parse, content length:', tab.content.length);
                 const html = marked.parse(tab.content);
-            let sanitizedHtml = DOMPurify.sanitize(html);
+                console.log('[_renderPreview] marked.parse returned type:', typeof html, 'isPromise:', html instanceof Promise);
+                if (html instanceof Promise) {
+                    console.error('[_renderPreview] marked.parse returned a Promise! Need to await it.');
+                    return;
+                }
+                sanitizedHtml = DOMPurify.sanitize(html);
+                console.log('[_renderPreview] DOMPurify.sanitize returned, length:', sanitizedHtml.length);
+
+                // Add to cache and maintain cache size limit (100 entries)
+                this.previewCache.set(contentHash, sanitizedHtml);
+                if (this.previewCache.size > 100) {
+                    const oldestKey = this.previewCache.keys().next().value;
+                    this.previewCache.delete(oldestKey);
+                }
+            }
 
             // TOC generation
             if (sanitizedHtml.includes('[[toc]]') || sanitizedHtml.includes('[TOC]')) {
@@ -1323,10 +1444,22 @@ class TabManager {
         }
     }
     
+    checkForLargeFile(tab, content) {
+        if (content && content.length > 1024 * 1024) { // >1MB
+            tab.largeFileMode = true;
+            this.isPreviewVisible = false;
+            this.updatePreviewVisibility();
+            notifyUser('Large file detected (>1MB). Large File Mode enabled to maintain peak responsiveness. Live preview auto-render is disabled.', 'warning');
+        } else {
+            tab.largeFileMode = false;
+        }
+    }
+
     // File operations
     openFile(filePath, content) {
         console.log('openFile called with:', filePath, 'content length:', content.length);
         let tab = this.tabs.get(this.activeTabId);
+        console.log('openFile tab state before:', { id: tab?.id, hasEditorView: !!tab?.editorView, contentLength: tab?.content?.length, filePath: tab?.filePath, isDirty: tab?.isDirty });
 
         // Handle both forward and back slashes for cross-platform compatibility
         const fileName = filePath.split(/[\\/]/).pop();
@@ -1340,24 +1473,31 @@ class TabManager {
             tab.originalContent = content;
             tab.isDirty = false;
 
+            this.checkForLargeFile(tab, content);
+
             // Update the editor and preview
             this.setEditorContent(this.activeTabId, content);
-            this.updatePreview(this.activeTabId);
+            console.log('openFile after setEditorContent, tab state:', { id: tab.id, hasEditorView: !!tab.editorView, contentLength: tab.content.length });
+            this.updatePreview(this.activeTabId, true); // immediate=true for initial load
             this.updateWordCount();
         } else {
             // Create new tab for the file
             console.log('Creating new tab for file');
             this.createNewTab();
             tab = this.tabs.get(this.activeTabId);
+            console.log('openFile after createNewTab, tab:', { id: tab.id, hasEditorView: !!tab.editorView });
             tab.filePath = filePath;
             tab.title = fileName;
             tab.content = content;
             tab.originalContent = content;
             tab.isDirty = false;
 
+            this.checkForLargeFile(tab, content);
+
             // Set content in the CodeMirror editor
             this.setEditorContent(this.activeTabId, content);
-            this.updatePreview(this.activeTabId);
+            console.log('openFile after setEditorContent, tab state:', { id: tab.id, hasEditorView: !!tab.editorView, contentLength: tab.content.length });
+            this.updatePreview(this.activeTabId, true); // immediate=true for initial load
             this.updateWordCount();
         }
         this.startAutoSave();
@@ -1365,6 +1505,7 @@ class TabManager {
         this.updateTabBar();
         this.updateFilePath();
         this.updateBreadcrumb();
+        this.updateUI(); // Ensure tab content is visible
 
         // Notify main process about current file for exports
         ipcRenderer.send('set-current-file', filePath);
@@ -1439,11 +1580,25 @@ class TabManager {
 let tabManager;
 let replPanel;
 
-document.addEventListener('DOMContentLoaded', () => {
+document.addEventListener('DOMContentLoaded', async () => {
+    const ModalManager = _ModalManager;
     tabManager = new TabManager();
+
+    // Load saved Custom Preview CSS if present
+    const savedCSSContent = localStorage.getItem('customPreviewCSSContent');
+    if (savedCSSContent) {
+        applyCustomPreviewCSS(savedCSSContent);
+    }
+
     const ReplPanel = getReplPanel();
     replPanel = new ReplPanel();
 
+    // Populate app version from main process
+    window.electronAPI.getAppVersion().then((version) => {
+      const el = document.getElementById('app-version-display');
+      if (el) el.textContent = `v${version}`;
+    });
+
     // Initialize ModalManager for all dialogs
     const findModal = new ModalManager('#find-dialog');
     const exportModal = new ModalManager('#export-dialog');
@@ -1473,7 +1628,7 @@ document.addEventListener('DOMContentLoaded', () => {
     // Initialize sidebar
     const SidebarManager = getSidebarManager();
     const sidebarManager = new SidebarManager();
-    let explorerCurrentDir = null;
+    const explorerCurrentDir = null;
 
     sidebarManager.registerPanel('explorer', {
         title: 'Explorer',
@@ -1545,6 +1700,63 @@ document.addEventListener('DOMContentLoaded', () => {
         }
     });
 
+    // --- Plugin System ---
+    const { PluginLoader } = require('./plugins/plugin-loader');
+    const { PluginRegistry } = require('./plugins/plugin-registry');
+    const { EventBus } = require('./plugins/event-bus');
+    const { SettingsStore } = require('./plugins/settings-store');
+    const pluginPath = require('path');
+
+    const pluginEventBus = new EventBus();
+    const pluginSettings = new SettingsStore({
+        get: (key) => window.electronAPI.invoke('plugin-settings:get', key),
+        set: (key, value) => window.electronAPI.invoke('plugin-settings:set', { key, value })
+    });
+
+    const statusBarRight = document.querySelector('.status-bar-right');
+
+    // Initialize command palette
+    const CommandPalette = getCommandPalette();
+    const commandPalette = new CommandPalette();
+
+    const pluginRegistry = new PluginRegistry({
+        sidebar: sidebarManager,
+        commands: commandPalette,
+        statusBar: {
+            registerIndicator: (id, opts) => {
+                const el = document.createElement('span');
+                el.className = 'status-item';
+                el.id = `plugin-status-${id}`;
+                if (opts.tooltip) el.title = opts.tooltip;
+                el.textContent = opts.text || '';
+                const sep = document.createElement('span');
+                sep.className = 'status-separator';
+                sep.textContent = '|';
+                if (statusBarRight) {
+                    statusBarRight.appendChild(sep);
+                    statusBarRight.appendChild(el);
+                }
+            }
+        },
+        eventBus: pluginEventBus,
+        settings: pluginSettings,
+        editor: {
+            getContent: () => tabManager.getCurrentContent(),
+            getSelection: () => tabManager.getSelection(),
+            insertAtCursor: (text) => tabManager.insertAtCursor(text),
+            onContentChanged: (cb) => pluginEventBus.on('document:changed', cb)
+        },
+        ipc: {
+            invoke: (ch, data) => window.electronAPI.invoke(ch, data),
+            on: (ch, cb) => window.electronAPI.on(ch, cb)
+        }
+    });
+
+    const builtInDir = pluginPath.join(__dirname, 'plugins', 'built-in');
+    const loader = new PluginLoader([builtInDir]);
+    const discovered = loader.discoverPlugins();
+    discovered.forEach(p => pluginRegistry.register(p));
+
     // Initialize Zen Mode
     const ZenModeClass = getZenMode();
     const zenMode = new ZenModeClass(tabManager);
@@ -1558,7 +1770,8 @@ document.addEventListener('DOMContentLoaded', () => {
 
         // Set welcome content in the first tab's preview
         const recentFiles = JSON.parse(localStorage.getItem('recentFiles') || '[]');
-        const welcomeHtml = getCreateWelcomeContent()(recentFiles);
+        const appVersion = await window.electronAPI.getAppVersion().catch(() => '');
+        const welcomeHtml = getCreateWelcomeContent()(recentFiles, appVersion);
 
         const tab = tabManager.tabs.get(tabManager.activeTabId);
         if (tab) {
@@ -1642,10 +1855,6 @@ document.addEventListener('DOMContentLoaded', () => {
         }
     });
 
-    // Initialize command palette
-    const CommandPalette = getCommandPalette();
-    const commandPalette = new CommandPalette();
-
     // Initialize print preview
     const PrintPreview = getPrintPreview();
     const printPreview = new PrintPreview();
@@ -1703,6 +1912,8 @@ document.addEventListener('DOMContentLoaded', () => {
     commandPalette.register('Insert Image', '', () => tabManager.wrapSelection('![', '](image.jpg)'));
     commandPalette.register('Toggle Zen Mode', 'F11', () => zenMode.toggle());
     commandPalette.register('Writing Analytics', 'Ctrl+Shift+A', () => getShowAnalyticsModal()(tabManager));
+    commandPalette.register('Load Custom Preview CSS', '', triggerLoadCustomCSS);
+    commandPalette.register('Clear Custom Preview CSS', '', triggerClearCustomCSS);
 
     // Keyboard shortcuts
     document.addEventListener('keydown', (e) => {
@@ -1772,6 +1983,7 @@ document.addEventListener('DOMContentLoaded', () => {
     }, 30000);
 });
 
+// IPC event listeners
 // IPC event listeners
 ipcRenderer.on('file-new', () => {
     tabManager.createNewTab();
@@ -1779,8 +1991,20 @@ ipcRenderer.on('file-new', () => {
 
 ipcRenderer.on('file-opened', (event, data) => {
     console.log('[RENDERER] file-opened received:', data.path, 'content length:', data.content.length);
+    console.log('[RENDERER] activeTabId before openFile:', tabManager.activeTabId);
+    // Diagnostic: check library state
+    console.log('[RENDERER] Library state:', {
+        marked: typeof marked,
+        DOMPurify: typeof DOMPurify,
+        markedParse: typeof marked?.parse,
+        dompurifySanitize: typeof DOMPurify?.sanitize,
+        tabManagerExists: !!tabManager
+    });
     if (tabManager) {
         tabManager.openFile(data.path, data.content);
+        console.log('[RENDERER] activeTabId after openFile:', tabManager.activeTabId);
+        const tab = tabManager.tabs.get(tabManager.activeTabId);
+        console.log('[RENDERER] tab state:', { id: tab?.id, hasEditorView: !!tab?.editorView, contentLength: tab?.content?.length });
     } else {
         console.error('[RENDERER] tabManager not initialized!');
     }
@@ -1859,6 +2083,49 @@ ipcRenderer.on('redo', () => {
     }
 });
 
+// Custom Preview CSS event handlers and trigger helpers
+function applyCustomPreviewCSS(cssContent) {
+    let styleTag = document.getElementById('custom-preview-style');
+    if (!styleTag) {
+        styleTag = document.createElement('style');
+        styleTag.id = 'custom-preview-style';
+        document.head.appendChild(styleTag);
+    }
+    const scopedCSS = scopeCSS(cssContent, '.preview-content');
+    styleTag.textContent = scopedCSS;
+}
+
+async function triggerLoadCustomCSS() {
+    try {
+        const result = await window.electronAPI.invoke('select-custom-css');
+        if (result) {
+            console.log('[RENDERER] Custom CSS loaded from:', result.path);
+            localStorage.setItem('customPreviewCSSPath', result.path);
+            localStorage.setItem('customPreviewCSSContent', result.content);
+            applyCustomPreviewCSS(result.content);
+            notifyUser('Custom preview stylesheet applied successfully.', 'success');
+        }
+    } catch (err) {
+        console.error('[RENDERER] Error loading custom CSS:', err);
+        notifyUser('Failed to load custom CSS stylesheet.', 'error');
+    }
+}
+
+function triggerClearCustomCSS() {
+    localStorage.removeItem('customPreviewCSSPath');
+    localStorage.removeItem('customPreviewCSSContent');
+    const styleTag = document.getElementById('custom-preview-style');
+    if (styleTag) {
+        styleTag.remove();
+    }
+    notifyUser('Custom preview stylesheet cleared.', 'info');
+}
+
+ipcRenderer.on('load-custom-css', triggerLoadCustomCSS);
+ipcRenderer.on('clear-custom-css', triggerClearCustomCSS);
+
+
+
 // Font size adjustment
 let currentFontSize = parseInt(localStorage.getItem('fontSize')) || 15;
 
@@ -1978,13 +2245,39 @@ function initializeExportForm(format) {
     document.getElementById('export-citeproc').checked = false;
     document.getElementById('export-toc-depth').value = 3;
 
-    // PDF-specific fields
+    // Toggle and reset PDF-specific fields
+    const pdfOnly = document.querySelector('.pdf-only');
+    if (pdfOnly) {
+        pdfOnly.style.display = (format === 'pdf') ? 'block' : 'none';
+    }
     if (format === 'pdf') {
         document.getElementById('pdf-engine').value = 'xelatex';
         document.getElementById('pdf-geometry').value = 'margin=1in';
         document.getElementById('custom-geometry').style.display = 'none';
     }
 
+    // Toggle and reset Reveal.js-specific fields
+    const revealjsOnly = document.querySelector('.revealjs-only');
+    if (revealjsOnly) {
+        revealjsOnly.style.display = (format === 'revealjs') ? 'block' : 'none';
+    }
+    const revealTheme = document.getElementById('reveal-theme');
+    if (revealTheme) revealTheme.value = 'black';
+    const revealTransition = document.getElementById('reveal-transition');
+    if (revealTransition) revealTransition.value = 'slide';
+    const revealSpeed = document.getElementById('reveal-speed');
+    if (revealSpeed) revealSpeed.value = 'default';
+    const revealSlideNumber = document.getElementById('reveal-slide-number');
+    if (revealSlideNumber) revealSlideNumber.checked = false;
+    const revealControls = document.getElementById('reveal-controls');
+    if (revealControls) revealControls.checked = true;
+    const revealProgress = document.getElementById('reveal-progress');
+    if (revealProgress) revealProgress.checked = true;
+    const revealHistory = document.getElementById('reveal-history');
+    if (revealHistory) revealHistory.checked = true;
+    const revealCenter = document.getElementById('reveal-center');
+    if (revealCenter) revealCenter.checked = true;
+
     // Clear bibliography fields
     document.getElementById('bibliography-file').value = '';
     document.getElementById('csl-file').value = '';
@@ -2044,6 +2337,18 @@ function collectExportOptions() {
             }
         }
 
+        // Reveal.js-specific options
+        if (currentExportFormat === 'revealjs') {
+            options.revealTheme = document.getElementById('reveal-theme').value;
+            options.revealTransition = document.getElementById('reveal-transition').value;
+            options.revealTransitionSpeed = document.getElementById('reveal-speed').value;
+            options.revealSlideNumber = document.getElementById('reveal-slide-number').checked;
+            options.revealControls = document.getElementById('reveal-controls').checked;
+            options.revealProgress = document.getElementById('reveal-progress').checked;
+            options.revealHistory = document.getElementById('reveal-history').checked;
+            options.revealCenter = document.getElementById('reveal-center').checked;
+        }
+
         // Bibliography
         const bibFile = document.getElementById('bibliography-file').value.trim();
         const cslFile = document.getElementById('csl-file').value.trim();
@@ -2054,6 +2359,15 @@ function collectExportOptions() {
         if (currentExportFormat === 'pdf') {
             options.pdfEngine = 'xelatex';
             options.geometry = 'margin=1in';
+        } else if (currentExportFormat === 'revealjs') {
+            options.revealTheme = 'black';
+            options.revealTransition = 'slide';
+            options.revealTransitionSpeed = 'default';
+            options.revealSlideNumber = false;
+            options.revealControls = true;
+            options.revealProgress = true;
+            options.revealHistory = true;
+            options.revealCenter = true;
         }
     }
 
@@ -2971,6 +3285,18 @@ function showPDFEditorDialog(operation, openedFilePath = null) {
         section.classList.add('hidden');
     });
 
+    // Hide visual thumbnail sidebar by default
+    const sidebar = document.getElementById('pdf-thumbnail-sidebar');
+    if (sidebar) {
+        sidebar.classList.add('hidden');
+    }
+    const body = document.querySelector('.pdf-editor-body');
+    if (body) {
+        body.classList.remove('side-by-side');
+    }
+    pdfDocInstance = null;
+    pdfPreviewState = { pages: [], filePath: '' };
+
     // Show the appropriate section and set title
     let sectionId, titleText;
     switch (operation) {
@@ -3004,7 +3330,11 @@ function showPDFEditorDialog(operation, openedFilePath = null) {
             titleText = 'Rotate Pages';
             if (openedFilePath) {
                 const rotateInput = document.getElementById('rotate-input-path');
-                if (rotateInput) rotateInput.value = openedFilePath;
+                if (rotateInput) {
+                    rotateInput.value = openedFilePath;
+                    // Trigger thumbnail generation
+                    setTimeout(() => onPDFFileSelected('rotate-input-path', openedFilePath), 50);
+                }
             }
             break;
         case 'delete':
@@ -3012,7 +3342,11 @@ function showPDFEditorDialog(operation, openedFilePath = null) {
             titleText = 'Delete Pages';
             if (openedFilePath) {
                 const deleteInput = document.getElementById('delete-input-path');
-                if (deleteInput) deleteInput.value = openedFilePath;
+                if (deleteInput) {
+                    deleteInput.value = openedFilePath;
+                    // Trigger thumbnail generation
+                    setTimeout(() => onPDFFileSelected('delete-input-path', openedFilePath), 50);
+                }
             }
             break;
         case 'reorder':
@@ -3020,7 +3354,11 @@ function showPDFEditorDialog(operation, openedFilePath = null) {
             titleText = 'Reorder Pages';
             if (openedFilePath) {
                 const reorderInput = document.getElementById('reorder-input-path');
-                if (reorderInput) reorderInput.value = openedFilePath;
+                if (reorderInput) {
+                    reorderInput.value = openedFilePath;
+                    // Trigger thumbnail generation
+                    setTimeout(() => onPDFFileSelected('reorder-input-path', openedFilePath), 50);
+                }
             }
             break;
         case 'watermark':
@@ -3181,6 +3519,7 @@ document.addEventListener('DOMContentLoaded', () => {
                         const file = e.target.files[0];
                         if (file) {
                             document.getElementById(button.inputId).value = file.path;
+                            onPDFFileSelected(button.inputId, file.path);
                         }
                     };
                     input.click();
@@ -3190,6 +3529,7 @@ document.addEventListener('DOMContentLoaded', () => {
                         const file = e.target.files[0];
                         if (file) {
                             document.getElementById(button.inputId).value = file.path;
+                            onPDFFileSelected(button.inputId, file.path);
                         }
                     };
                     input.click();
@@ -3334,7 +3674,7 @@ function showPDFValidationMessage(message, focusSelector = null) {
 // Process PDF Operation
 function processPDFOperation() {
     const operation = currentPDFOperation;
-    let operationData = { operation };
+    const operationData = { operation };
 
     try {
         switch (operation) {
@@ -4124,7 +4464,7 @@ function textToASCII(text, style) {
         lines[i] = '';
     }
 
-    for (let char of upperText) {
+    for (const char of upperText) {
         const charLines = font.chars[char] || font.chars[' '];
         if (charLines) {
             for (let i = 0; i < font.height; i++) {
@@ -4162,7 +4502,7 @@ function createASCIIBox(text, style, padding) {
     }
 
     // Content lines
-    for (let line of lines) {
+    for (const line of lines) {
         const paddedLine = line.padEnd(maxLength, ' ');
         result += chars.v + ' '.repeat(padding) + paddedLine + ' '.repeat(padding) + chars.v + '\n';
     }
@@ -4798,3 +5138,224 @@ ipcRenderer.on('show-video-tool', (event, tool) => {
         { duration: 5000 }
     );
 });
+
+// ============================================
+// PDF EDITOR VISUAL PAGE SIDEBAR HANDLERS
+// ============================================
+let pdfDocInstance = null;
+let pdfPreviewState = { pages: [], filePath: '' };
+
+function onPDFFileSelected(inputId, filePath) {
+    const eligibleInputs = ['rotate-input-path', 'delete-input-path', 'reorder-input-path'];
+    if (!eligibleInputs.includes(inputId)) {
+        return;
+    }
+
+    const sidebar = document.getElementById('pdf-thumbnail-sidebar');
+    if (sidebar) {
+        sidebar.classList.remove('hidden');
+    }
+    const body = document.querySelector('.pdf-editor-body');
+    if (body) {
+        body.classList.add('side-by-side');
+    }
+
+    loadPDFThumbnails(filePath);
+}
+
+async function loadPDFThumbnails(filePath) {
+    const grid = document.getElementById('pdf-thumbnail-grid');
+    if (!grid) return;
+
+    // Reset previous inputs
+    const rotateInput = document.getElementById('rotate-pages');
+    if (rotateInput) rotateInput.value = '';
+    const deleteInput = document.getElementById('delete-pages');
+    if (deleteInput) deleteInput.value = '';
+    const reorderInput = document.getElementById('reorder-pages');
+    if (reorderInput) reorderInput.value = '';
+
+    grid.innerHTML = '<div class="loading-thumbnails">Loading page thumbnails...</div>';
+
+    try {
+        const pdfjs = getPdfjsLib();
+        const loadingTask = pdfjs.getDocument(filePath);
+        pdfDocInstance = await loadingTask.promise;
+
+        pdfPreviewState.filePath = filePath;
+        pdfPreviewState.pages = [];
+
+        for (let i = 1; i <= pdfDocInstance.numPages; i++) {
+            pdfPreviewState.pages.push({
+                originalPageNum: i,
+                rotation: 0,
+                isDeleted: false
+            });
+        }
+
+        renderThumbnailGrid();
+    } catch (err) {
+        console.error('Error loading PDF thumbnails:', err);
+        grid.innerHTML = '<div class="thumbnail-error">Failed to load PDF thumbnails.</div>';
+    }
+}
+
+function renderThumbnailGrid() {
+    const grid = document.getElementById('pdf-thumbnail-grid');
+    if (!grid || !pdfDocInstance) return;
+
+    grid.innerHTML = '';
+
+    pdfPreviewState.pages.forEach((pageInfo, index) => {
+        const card = document.createElement('div');
+        card.className = 'pdf-thumbnail-card';
+        if (pageInfo.isDeleted) {
+            card.classList.add('marked-delete');
+        }
+
+        const heading = document.createElement('div');
+        heading.className = 'pdf-thumbnail-header';
+        heading.innerHTML = `<span class="badge">Page ${pageInfo.originalPageNum}</span>`;
+
+        const canvasContainer = document.createElement('div');
+        canvasContainer.className = 'canvas-container';
+
+        const canvas = document.createElement('canvas');
+        canvas.className = 'pdf-thumbnail-canvas';
+        if (pageInfo.rotation > 0) {
+            canvas.classList.add('rot' + pageInfo.rotation);
+        }
+        canvasContainer.appendChild(canvas);
+
+        // Render thumbnail canvas
+        renderThumbnail(pdfDocInstance, pageInfo.originalPageNum, canvas, pageInfo.rotation);
+
+        const controlsRow = document.createElement('div');
+        controlsRow.className = 'pdf-thumbnail-controls';
+
+        // Rotate Button
+        const rotateBtn = document.createElement('button');
+        rotateBtn.type = 'button';
+        rotateBtn.className = 'btn-rotate-thumbnail';
+        rotateBtn.innerHTML = '↻ Rotate 90°';
+        rotateBtn.addEventListener('click', () => {
+            pageInfo.rotation = (pageInfo.rotation + 90) % 360;
+            canvas.className = 'pdf-thumbnail-canvas';
+            if (pageInfo.rotation > 0) {
+                canvas.classList.add('rot' + pageInfo.rotation);
+            }
+            renderThumbnail(pdfDocInstance, pageInfo.originalPageNum, canvas, pageInfo.rotation);
+            syncRotateInput();
+        });
+
+        // Delete Checkbox
+        const deleteLabel = document.createElement('label');
+        deleteLabel.className = 'delete-thumbnail-checkbox';
+
+        const deleteChk = document.createElement('input');
+        deleteChk.type = 'checkbox';
+        deleteChk.checked = pageInfo.isDeleted;
+        deleteChk.addEventListener('change', (e) => {
+            pageInfo.isDeleted = e.target.checked;
+            card.classList.toggle('marked-delete', pageInfo.isDeleted);
+            syncDeleteInput();
+        });
+        deleteLabel.appendChild(deleteChk);
+        deleteLabel.appendChild(document.createTextNode(' Delete'));
+
+        // Reorder buttons
+        const reorderDiv = document.createElement('div');
+        reorderDiv.className = 'pdf-thumbnail-reorder';
+
+        const leftBtn = document.createElement('button');
+        leftBtn.type = 'button';
+        leftBtn.className = 'btn-reorder-left';
+        leftBtn.innerHTML = '◀';
+        leftBtn.disabled = (index === 0);
+        leftBtn.addEventListener('click', () => {
+            const temp = pdfPreviewState.pages[index];
+            pdfPreviewState.pages[index] = pdfPreviewState.pages[index - 1];
+            pdfPreviewState.pages[index - 1] = temp;
+            renderThumbnailGrid();
+            syncReorderInput();
+        });
+
+        const rightBtn = document.createElement('button');
+        rightBtn.type = 'button';
+        rightBtn.className = 'btn-reorder-right';
+        rightBtn.innerHTML = '▶';
+        rightBtn.disabled = (index === pdfPreviewState.pages.length - 1);
+        rightBtn.addEventListener('click', () => {
+            const temp = pdfPreviewState.pages[index];
+            pdfPreviewState.pages[index] = pdfPreviewState.pages[index + 1];
+            pdfPreviewState.pages[index + 1] = temp;
+            renderThumbnailGrid();
+            syncReorderInput();
+        });
+
+        reorderDiv.appendChild(leftBtn);
+        reorderDiv.appendChild(rightBtn);
+
+        controlsRow.appendChild(rotateBtn);
+        controlsRow.appendChild(deleteLabel);
+        controlsRow.appendChild(reorderDiv);
+
+        card.appendChild(heading);
+        card.appendChild(canvasContainer);
+        card.appendChild(controlsRow);
+
+        grid.appendChild(card);
+    });
+}
+
+async function renderThumbnail(pdfDoc, originalPageNum, canvasElement, rotation) {
+    try {
+        const page = await pdfDoc.getPage(originalPageNum);
+        const ctx = canvasElement.getContext('2d');
+
+        // Render at a fixed width of 100px
+        const unscaledViewport = page.getViewport({ scale: 1, rotation: 0 });
+        const scale = 100 / unscaledViewport.width;
+        const viewport = page.getViewport({ scale: scale, rotation: 0 });
+
+        canvasElement.width = viewport.width;
+        canvasElement.height = viewport.height;
+
+        await page.render({
+            canvasContext: ctx,
+            viewport: viewport
+        }).promise;
+    } catch (err) {
+        console.error('Error rendering page canvas:', err);
+    }
+}
+
+function syncRotateInput() {
+    const rotatedPages = pdfPreviewState.pages
+        .filter(p => p.rotation > 0)
+        .map(p => p.originalPageNum);
+
+    const rotateInput = document.getElementById('rotate-pages');
+    if (rotateInput) {
+        rotateInput.value = rotatedPages.join(', ');
+    }
+}
+
+function syncDeleteInput() {
+    const deletedPages = pdfPreviewState.pages
+        .filter(p => p.isDeleted)
+        .map(p => p.originalPageNum);
+
+    const deleteInput = document.getElementById('delete-pages');
+    if (deleteInput) {
+        deleteInput.value = deletedPages.join(', ');
+    }
+}
+
+function syncReorderInput() {
+    const order = pdfPreviewState.pages.map(p => p.originalPageNum);
+    const reorderInput = document.getElementById('reorder-pages');
+    if (reorderInput) {
+        reorderInput.value = order.join(', ');
+    }
+}

src/styles-modern.css

@@ -2372,3 +2372,254 @@ body[class*="dark"] .breadcrumb-bar {
 @keyframes analyticsSlideUp { from{transform:translateY(16px);opacity:0} to{transform:translateY(0);opacity:1} }
 body[class*="dark"] .analytics-modal { background:var(--gray-800,#1f2937); }
 body[class*="dark"] .word-tag { background:var(--gray-700,#374151); }
+
+/* ========================================
+   Interactive PDF Thumbnail Sidebar Styles
+   ======================================== */
+.pdf-editor-body.side-by-side {
+  display: flex;
+  flex-direction: row;
+  gap: 16px;
+  height: 550px;
+  overflow: hidden;
+}
+
+.pdf-editor-left-panel {
+  flex: 1.2;
+  overflow-y: auto;
+  padding-right: 8px;
+  height: 100%;
+}
+
+.pdf-editor-right-panel {
+  flex: 0.8;
+  display: flex;
+  flex-direction: column;
+  border-left: 1px solid var(--border-color, #e5e7eb);
+  padding-left: 16px;
+  height: 100%;
+  overflow: hidden;
+}
+
+.pdf-editor-right-panel h4 {
+  margin: 0 0 4px 0;
+  font-size: 15px;
+  font-weight: 600;
+  color: var(--text-primary);
+}
+
+.pdf-editor-right-panel .sidebar-help {
+  margin: 0 0 12px 0;
+  font-size: 11px;
+  color: var(--text-secondary, #6b7280);
+  line-height: 1.4;
+}
+
+.pdf-thumbnail-grid {
+  flex: 1;
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
+  gap: 12px;
+  overflow-y: auto;
+  padding: 4px;
+}
+
+.pdf-thumbnail-card {
+  display: flex;
+  flex-direction: column;
+  border: 1px solid var(--border-color, #e5e7eb);
+  border-radius: 8px;
+  background: var(--bg-primary, #ffffff);
+  box-shadow: var(--shadow-sm);
+  padding: 8px;
+  transition: all var(--transition-speed, 0.3s) var(--transition-ease);
+  position: relative;
+  overflow: hidden;
+}
+
+.pdf-thumbnail-card:hover {
+  transform: translateY(-2px);
+  box-shadow: var(--shadow-md);
+  border-color: var(--primary-light, #8b9aff);
+}
+
+.pdf-thumbnail-card.marked-delete {
+  border-color: var(--error, #ef4444);
+  background: rgba(239, 68, 68, 0.05);
+}
+
+.pdf-thumbnail-card.marked-delete::after {
+  content: "DELETE";
+  position: absolute;
+  top: 50%;
+  left: 50%;
+  transform: translate(-50%, -50%) rotate(-15deg);
+  background: rgba(239, 68, 68, 0.95);
+  color: #fff;
+  font-size: 10px;
+  font-weight: 700;
+  padding: 4px 8px;
+  border-radius: 4px;
+  pointer-events: none;
+  box-shadow: var(--shadow-sm);
+  letter-spacing: 0.5px;
+  white-space: nowrap;
+}
+
+.pdf-thumbnail-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  margin-bottom: 6px;
+}
+
+.pdf-thumbnail-header .badge {
+  font-size: 11px;
+  font-weight: 600;
+  background: var(--bg-tertiary, #f3f4f6);
+  color: var(--text-primary);
+  padding: 2px 6px;
+  border-radius: 4px;
+  font-family: var(--font-mono, monospace);
+}
+
+.canvas-container {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  background: var(--bg-secondary, #f9fafb);
+  border: 1px solid var(--border-color, #e5e7eb);
+  border-radius: 6px;
+  padding: 6px;
+  height: 120px;
+  overflow: hidden;
+}
+
+.pdf-thumbnail-canvas {
+  max-width: 100%;
+  max-height: 100%;
+  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
+  transition: transform 0.3s ease;
+}
+
+/* CSS Rotations */
+.rot90 {
+  transform: rotate(90deg);
+}
+.rot180 {
+  transform: rotate(180deg);
+}
+.rot270 {
+  transform: rotate(270deg);
+}
+
+.pdf-thumbnail-controls {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+  margin-top: 8px;
+}
+
+.pdf-thumbnail-controls button,
+.pdf-thumbnail-controls label {
+  font-size: 11px;
+}
+
+.btn-rotate-thumbnail {
+  background: var(--bg-tertiary, #f3f4f6);
+  border: 1px solid var(--border-color, #e5e7eb);
+  color: var(--text-primary);
+  border-radius: 4px;
+  padding: 3px 6px;
+  cursor: pointer;
+  width: 100%;
+  text-align: center;
+  transition: all 0.2s;
+  font-weight: 500;
+}
+
+.btn-rotate-thumbnail:hover {
+  background: var(--primary-light, #8b9aff);
+  color: #fff;
+  border-color: var(--primary-dark);
+}
+
+.delete-thumbnail-checkbox {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 4px;
+  cursor: pointer;
+  user-select: none;
+  font-weight: 500;
+  color: var(--text-secondary);
+}
+
+.delete-thumbnail-checkbox input {
+  margin: 0;
+  cursor: pointer;
+}
+
+.pdf-thumbnail-reorder {
+  display: flex;
+  justify-content: space-between;
+  gap: 4px;
+}
+
+.btn-reorder-left,
+.btn-reorder-right {
+  flex: 1;
+  background: var(--bg-tertiary, #f3f4f6);
+  border: 1px solid var(--border-color, #e5e7eb);
+  color: var(--text-primary);
+  border-radius: 4px;
+  padding: 2px;
+  cursor: pointer;
+  transition: all 0.2s;
+}
+
+.btn-reorder-left:hover:not(:disabled),
+.btn-reorder-right:hover:not(:disabled) {
+  background: var(--bg-secondary);
+  border-color: var(--text-muted);
+}
+
+.btn-reorder-left:disabled,
+.btn-reorder-right:disabled {
+  opacity: 0.3;
+  cursor: not-allowed;
+}
+
+.loading-thumbnails,
+.thumbnail-error {
+  grid-column: 1 / -1;
+  text-align: center;
+  padding: 40px 20px;
+  font-size: 13px;
+  color: var(--text-muted);
+}
+
+.thumbnail-error {
+  color: var(--error, #ef4444);
+}
+
+/* Dark mode adjustments */
+body[class*="dark"] .pdf-thumbnail-card {
+  background: var(--gray-800, #1f2937);
+  border-color: var(--gray-700, #374151);
+}
+body[class*="dark"] .pdf-thumbnail-header .badge {
+  background: var(--gray-700, #374151);
+  color: var(--gray-200);
+}
+body[class*="dark"] .canvas-container {
+  background: var(--gray-900, #111827);
+  border-color: var(--gray-700);
+}
+body[class*="dark"] .btn-rotate-thumbnail,
+body[class*="dark"] .btn-reorder-left,
+body[class*="dark"] .btn-reorder-right {
+  background: var(--gray-700, #374151);
+  border-color: var(--gray-600);
+  color: var(--gray-200);
+}

src/utils/ModalManager.js

@@ -1,6 +1,6 @@
 /**
  * ModalManager - Unified modal system with accessibility support
- * @version 4.1.0
+ * @version 4.4.3
  */
 class ModalManager {
     #modal;
@@ -237,8 +237,8 @@ class ModalManager {
     }
 }
 
-// Export for use in renderer
+// Export for use in renderer - avoid duplicate declaration
-if (typeof window !== 'undefined') {
+if (typeof window !== 'undefined' && !window.ModalManager) {
     window.ModalManager = ModalManager;
 }
 

src/welcome.js

@@ -1,4 +1,4 @@
-function createWelcomeContent(recentFiles = []) {
+function createWelcomeContent(recentFiles = [], appVersion = '') {
     const recentHtml = recentFiles.length
         ? recentFiles.map(f => {
             const name = f.split(/[/\\]/).pop();
@@ -10,7 +10,7 @@ function createWelcomeContent(recentFiles = []) {
     <div class="welcome-container">
         <div class="welcome-hero">
             <h1 class="welcome-title">MarkdownConverter</h1>
-            <p class="welcome-version">Version 4.1.0</p>
+            <p class="welcome-version">${appVersion ? `Version ${appVersion}` : ''}</p>
             <p class="welcome-subtitle">Professional Markdown Editor & Universal Document Converter</p>
         </div>
 

src/wordTemplateExporter.js

@@ -655,7 +655,7 @@ class WordTemplateExporter {
      */
     parseInlineFormatting(text) {
         let xml = '';
-        let pos = 0;
+        const pos = 0;
 
         // Patterns for inline formatting
         const patterns = [

src/zen-mode.js

@@ -117,7 +117,7 @@ class ZenMode {
     _applyTypewriterBehavior(view) {
         // We use a custom update listener that scrolls the cursor to center.
         // This is stored on the instance so we can clean it up.
-        let scrollTimeout = null;
+        const scrollTimeout = null;
 
         const scrollFn = () => {
             if (!this.active) return;

tests/event-bus.test.js

@@ -0,0 +1,64 @@
+const { EventBus } = require('../src/plugins/event-bus');
+
+describe('EventBus', () => {
+  let bus;
+
+  beforeEach(() => {
+    bus = new EventBus();
+  });
+
+  test('on/emit — listener receives payload', () => {
+    const received = [];
+    bus.on('document:saved', (payload) => received.push(payload));
+    bus.emit('document:saved', { filePath: '/test.md', tabId: 'tab1' });
+    expect(received).toEqual([{ filePath: '/test.md', tabId: 'tab1' }]);
+  });
+
+  test('on — ignores events with no listeners', () => {
+    expect(() => bus.emit('unknown:event', {})).not.toThrow();
+  });
+
+  test('off — removes specific listener', () => {
+    const handler = jest.fn();
+    bus.on('test:event', handler);
+    bus.off('test:event', handler);
+    bus.emit('test:event', {});
+    expect(handler).not.toHaveBeenCalled();
+  });
+
+  test('off — removes all listeners for event when no handler given', () => {
+    const h1 = jest.fn();
+    const h2 = jest.fn();
+    bus.on('test:event', h1);
+    bus.on('test:event', h2);
+    bus.off('test:event');
+    bus.emit('test:event', {});
+    expect(h1).not.toHaveBeenCalled();
+    expect(h2).not.toHaveBeenCalled();
+  });
+
+  test('hasHandler — returns true when listener exists', () => {
+    bus.on('ai:analyze', () => {});
+    expect(bus.hasHandler('ai:analyze')).toBe(true);
+  });
+
+  test('hasHandler — returns false when no listener exists', () => {
+    expect(bus.hasHandler('ai:analyze')).toBe(false);
+  });
+
+  test('handler errors are caught and logged, not thrown', () => {
+    const errorSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+    bus.on('bad:event', () => { throw new Error('boom'); });
+    expect(() => bus.emit('bad:event', {})).not.toThrow();
+    expect(errorSpy).toHaveBeenCalled();
+    errorSpy.mockRestore();
+  });
+
+  test('multiple listeners all receive the event', () => {
+    const results = [];
+    bus.on('multi:event', () => results.push('a'));
+    bus.on('multi:event', () => results.push('b'));
+    bus.emit('multi:event', {});
+    expect(results).toEqual(['a', 'b']);
+  });
+});

tests/git-operations.test.js

@@ -0,0 +1,123 @@
+/**
+ * Git Operations Utilities Test Suite
+ * Tests for async patterns and error handling
+ * @version 4.3.0
+ */
+
+describe('GitOperations Utilities', () => {
+  describe('error handling patterns', () => {
+    it('should handle git errors gracefully', () => {
+      const errorResponse = { error: 'Not a git repository' };
+      
+      expect(errorResponse).toHaveProperty('error');
+      expect(errorResponse.error).toContain('repository');
+    });
+
+    it('should return error object on failure', () => {
+      const failureResult = { error: 'Failed to commit' };
+      
+      expect(failureResult).toBeDefined();
+      expect(failureResult.error).toBeTruthy();
+    });
+  });
+
+  describe('async patterns', () => {
+    it('should handle async operations', async () => {
+      const asyncFn = async () => {
+        return { status: 'success' };
+      };
+
+      const result = await asyncFn();
+      expect(result).toHaveProperty('status');
+    });
+
+    it('should handle async errors', async () => {
+      const asyncFnWithError = async () => {
+        throw new Error('Git operation failed');
+      };
+
+      try {
+        await asyncFnWithError();
+        expect(true).toBe(false); // Should not reach here
+      } catch (err) {
+        expect(err.message).toContain('Git');
+      }
+    });
+  });
+
+  describe('git operations', () => {
+    it('should document expected operations', () => {
+      const gitOps = [
+        'getStatus',
+        'stage',
+        'commit',
+        'log',
+        'diff',
+        'branch',
+        'checkout',
+        'push',
+        'pull'
+      ];
+
+      expect(gitOps.length).toBeGreaterThan(0);
+      gitOps.forEach(op => {
+        expect(typeof op).toBe('string');
+        expect(op.length).toBeGreaterThan(0);
+      });
+    });
+
+    it('should handle directory paths', () => {
+      const paths = [
+        '/home/user/project',
+        './current/dir',
+        '../parent/dir'
+      ];
+
+      paths.forEach(pathStr => {
+        expect(typeof pathStr).toBe('string');
+        expect(pathStr.length).toBeGreaterThan(0);
+      });
+    });
+
+    it('should handle commit messages', () => {
+      const messages = [
+        'fix: bug in git panel',
+        'feat: add new feature',
+        'refactor: clean up code'
+      ];
+
+      messages.forEach(msg => {
+        expect(typeof msg).toBe('string');
+        expect(msg.length).toBeGreaterThan(0);
+      });
+    });
+  });
+
+  describe('response structures', () => {
+    it('should return status info', () => {
+      const statusResponse = {
+        conflicted: [],
+        created: [],
+        deleted: [],
+        modified: [],
+        renamed: [],
+        staged: ['file.md']
+      };
+
+      expect(statusResponse).toHaveProperty('staged');
+      expect(Array.isArray(statusResponse.staged)).toBe(true);
+    });
+
+    it('should return log entries', () => {
+      const logResponse = {
+        all: [
+          { hash: 'abc123', message: 'fix: something' }
+        ],
+        latest: { hash: 'abc123', message: 'fix: something' }
+      };
+
+      expect(logResponse).toHaveProperty('all');
+      expect(Array.isArray(logResponse.all)).toBe(true);
+    });
+  });
+});

tests/goal-tracker.test.js

@@ -0,0 +1,82 @@
+const { GoalTracker } = require('../src/plugins/built-in/writing-studio/goal-tracker');
+
+describe('GoalTracker', () => {
+  let tracker;
+  let store;
+
+  beforeEach(() => {
+    store = {};
+    tracker = new GoalTracker({
+      get: (key) => store[key],
+      set: (key, value) => { store[key] = value; }
+    });
+  });
+
+  test('addWords records words for today', () => {
+    tracker.addWords(500);
+    const today = new Date().toISOString().split('T')[0];
+    expect(store['plugins.writing-studio.history']).toBeDefined();
+    const history = JSON.parse(store['plugins.writing-studio.history']);
+    expect(history[today].words).toBe(500);
+  });
+
+  test('addWords accumulates across multiple calls', () => {
+    tracker.addWords(300);
+    tracker.addWords(200);
+    const today = new Date().toISOString().split('T')[0];
+    const history = JSON.parse(store['plugins.writing-studio.history']);
+    expect(history[today].words).toBe(500);
+  });
+
+  test('getDailyProgress returns 0 when no history', () => {
+    expect(tracker.getDailyProgress(1000)).toEqual({ written: 0, goal: 1000, pct: 0 });
+  });
+
+  test('getDailyProgress returns percentage', () => {
+    tracker.addWords(500);
+    const progress = tracker.getDailyProgress(1000);
+    expect(progress.written).toBe(500);
+    expect(progress.pct).toBe(50);
+  });
+
+  test('getStreak counts consecutive days meeting goal', () => {
+    const today = new Date();
+    for (let i = 0; i < 3; i++) {
+      const d = new Date(today);
+      d.setDate(d.getDate() - i);
+      const key = d.toISOString().split('T')[0];
+      tracker._setHistoryDay(key, { words: 1200 });
+    }
+    const streak = tracker.getStreak(1000);
+    expect(streak).toBe(3);
+  });
+
+  test('getStreak breaks on missed day', () => {
+    const today = new Date();
+    tracker._setHistoryDay(today.toISOString().split('T')[0], { words: 1200 });
+    const yesterday = new Date(today);
+    yesterday.setDate(yesterday.getDate() - 1);
+    tracker._setHistoryDay(yesterday.toISOString().split('T')[0], { words: 500 });
+    const dayBefore = new Date(today);
+    dayBefore.setDate(dayBefore.getDate() - 2);
+    tracker._setHistoryDay(dayBefore.toISOString().split('T')[0], { words: 1200 });
+    expect(tracker.getStreak(1000)).toBe(1);
+  });
+
+  test('getLast30Days returns array of 30 entries', () => {
+    tracker.addWords(100);
+    const days = tracker.getLast30Days();
+    expect(days.length).toBe(30);
+    expect(days[29].words).toBe(100);
+  });
+
+  test('getWeeklyTotal sums last 7 days', () => {
+    const today = new Date();
+    for (let i = 0; i < 7; i++) {
+      const d = new Date(today);
+      d.setDate(d.getDate() - i);
+      tracker._setHistoryDay(d.toISOString().split('T')[0], { words: 200 });
+    }
+    expect(tracker.getWeeklyTotal()).toBe(1400);
+  });
+});

tests/markdown-extensions.test.js

@@ -76,6 +76,75 @@ describe('Markdown Extensions', () => {
         });
     });
 
+    describe('Admonitions full parsing integration (mocked environment)', () => {
+        const extension = {
+            name: 'admonition',
+            level: 'block',
+            start(src) { return src.match(/^:::(note|warning|tip|danger|info)/m)?.index; },
+            tokenizer(src) {
+                const match = src.match(/^:::(note|warning|tip|danger|info)\s*\n([\s\S]*?)^:::\s*$/m);
+                if (match && match.index === 0) {
+                    const admonitionType = match[1];
+                    const text = match[2].trim();
+                    const tokens = [];
+                    this.lexer.blockTokens(text, tokens);
+                    return {
+                        type: 'admonition',
+                        raw: match[0],
+                        admonitionType,
+                        text,
+                        tokens
+                    };
+                }
+            },
+            renderer(token) {
+                const icons = { note: 'ℹ', warning: '⚠', tip: '💡', danger: '🔴', info: 'ℹ' };
+                const icon = icons[token.admonitionType] || 'ℹ';
+                const inner = this.parser.parse(token.tokens || []);
+                return `<div class="admonition admonition-${token.admonitionType}">
+                    <div class="admonition-title">${icon} ${token.admonitionType.charAt(0).toUpperCase() + token.admonitionType.slice(1)}</div>
+                    <div class="admonition-content">${inner}</div>
+                </div>`;
+            }
+        };
+
+        test('tokenizer correctly extracts tokens and calls blockTokens', () => {
+            const src = ':::note\nThis is a note.\n:::';
+            const mockLexer = {
+                blockTokens: jest.fn((text, tokens) => {
+                    tokens.push({ type: 'text', text });
+                })
+            };
+            const context = { lexer: mockLexer };
+            const result = extension.tokenizer.call(context, src);
+            
+            expect(result).toBeDefined();
+            expect(result.type).toBe('admonition');
+            expect(result.admonitionType).toBe('note');
+            expect(result.text).toBe('This is a note.');
+            expect(mockLexer.blockTokens).toHaveBeenCalledWith('This is a note.', expect.any(Array));
+            expect(result.tokens).toEqual([{ type: 'text', text: 'This is a note.' }]);
+        });
+
+        test('renderer correctly translates tokens to HTML', () => {
+            const token = {
+                type: 'admonition',
+                admonitionType: 'warning',
+                tokens: [{ type: 'text', text: 'Be careful!' }]
+            };
+            const mockParser = {
+                parse: jest.fn((tokens) => '<p>Be careful!</p>')
+            };
+            const context = { parser: mockParser };
+            const html = extension.renderer.call(context, token);
+            
+            expect(html).toContain('admonition admonition-warning');
+            expect(html).toContain('⚠ Warning');
+            expect(html).toContain('<p>Be careful!</p>');
+            expect(mockParser.parse).toHaveBeenCalledWith(token.tokens);
+        });
+    });
+
     describe('PlantUML hex encoding', () => {
         const plantumlEncode = (text) => {
             const hex = Array.from(Buffer.from(text, 'utf-8'))
@@ -127,4 +196,53 @@ describe('Markdown Extensions', () => {
             expect(slugify('simple')).toBe('simple');
         });
     });
+
+    describe('scopeCSS utility', () => {
+        const scopeCSS = (cssText, scopeSelector) => {
+            if (!cssText) return '';
+            return cssText.replace(/([^\r\n,{}]+)(,(?=[^}]*{)|(?=[^{]*{))/g, (match, selector, separator) => {
+                const trimmed = selector.trim();
+                if (!trimmed || trimmed.startsWith('@') || trimmed.startsWith(':root') || trimmed.startsWith('from') || trimmed.startsWith('to') || /^\d+%$/.test(trimmed)) {
+                    return match;
+                }
+                return scopeSelector + ' ' + trimmed + (separator || '');
+            });
+        };
+
+        test('scopes standard tag selector', () => {
+            const css = 'h1 { color: red; }';
+            const scoped = scopeCSS(css, '.preview-content');
+            expect(scoped).toBe('.preview-content h1{ color: red; }');
+        });
+
+        test('scopes multiple class selectors', () => {
+            const css = '.title, .content { font-family: sans-serif; }';
+            const scoped = scopeCSS(css, '.preview-content');
+            expect(scoped).toBe('.preview-content .title,.preview-content .content{ font-family: sans-serif; }');
+        });
+
+        test('ignores @rules like @media', () => {
+            const css = '@media (max-width: 600px) { h1 { color: blue; } }';
+            const scoped = scopeCSS(css, '.preview-content');
+            expect(scoped).toContain('@media (max-width: 600px)');
+        });
+
+        test('ignores :root selector', () => {
+            const css = ':root { --color: red; }';
+            const scoped = scopeCSS(css, '.preview-content');
+            expect(scoped).toBe(':root { --color: red; }');
+        });
+
+        test('ignores keyframe percentages', () => {
+            const css = '0% { opacity: 0; } 100% { opacity: 1; }';
+            const scoped = scopeCSS(css, '.preview-content');
+            expect(scoped).toContain('0%');
+            expect(scoped).toContain('100%');
+        });
+
+        test('handles empty input', () => {
+            expect(scopeCSS('', '.preview-content')).toBe('');
+            expect(scopeCSS(null, '.preview-content')).toBe('');
+        });
+    });
 });

tests/pdf-operations.test.js

@@ -0,0 +1,95 @@
+/**
+ * PDF Operations Utilities Test Suite
+ * Tests for helper functions and logic patterns
+ * @version 4.3.0
+ */
+
+describe('PDFOperations Utilities', () => {
+  describe('page range parsing', () => {
+    it('should parse single page numbers', () => {
+      // Test logic: parsing "1" should extract page index 0
+      const input = '1';
+      const pages = [0]; // Parsed result
+      
+      expect(pages.length).toBe(1);
+      expect(pages[0]).toBe(0);
+    });
+
+    it('should parse page ranges', () => {
+      // Test logic: parsing "1-3" should extract pages 0, 1, 2
+      const input = '1-3';
+      const pages = [0, 1, 2]; // Expected result
+      
+      expect(pages.length).toBe(3);
+      expect(pages).toEqual([0, 1, 2]);
+    });
+
+    it('should handle multiple ranges', () => {
+      // Test logic: parsing "1-2,4-5" should extract pages 0,1,3,4
+      const input = '1-2,4-5';
+      const pages = [0, 1, 3, 4]; // Expected result
+      
+      expect(pages.length).toBe(4);
+      expect(pages).toEqual([0, 1, 3, 4]);
+    });
+
+    it('should sort pages in ascending order', () => {
+      const unsorted = [2, 0, 3, 1];
+      const sorted = unsorted.sort((a, b) => a - b);
+      
+      expect(sorted).toEqual([0, 1, 2, 3]);
+    });
+  });
+
+  describe('hex color conversion', () => {
+    it('should validate hex color format', () => {
+      const validHex = '#FF5733';
+      const isValid = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.test(validHex);
+      
+      expect(isValid).toBe(true);
+    });
+
+    it('should detect invalid hex colors', () => {
+      const invalidColors = ['#GG5733', '#12345', 'notahex'];
+      
+      invalidColors.forEach(color => {
+        const isValid = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.test(color);
+        expect(isValid).toBe(false);
+      });
+    });
+  });
+
+  describe('error handling', () => {
+    it('should handle empty input', () => {
+      const input = '';
+      expect(input.length).toBe(0);
+      // Should not process empty strings
+      expect(input === '').toBe(true);
+    });
+
+    it('should handle invalid page numbers', () => {
+      const testPages = [
+        { input: '0', isValid: false },
+        { input: '-1', isValid: false },
+        { input: 'abc', isValid: false },
+        { input: '1', isValid: true },
+        { input: '5', isValid: true }
+      ];
+      
+      testPages.forEach(({ input, isValid }) => {
+        const num = parseInt(input);
+        
+        if (isNaN(num)) {
+          // Non-numeric string
+          expect(isValid).toBe(false);
+        } else if (num < 1) {
+          // Zero or negative
+          expect(isValid).toBe(false);
+        } else {
+          // Positive number
+          expect(isValid).toBe(true);
+        }
+      });
+    });
+  });
+});

tests/plugin-api.test.js

@@ -0,0 +1,29 @@
+const { PluginAPI } = require('../src/plugins/plugin-api');
+
+describe('PluginAPI', () => {
+  test('has default no-op lifecycle methods', () => {
+    const plugin = new PluginAPI();
+    expect(() => plugin.init({})).not.toThrow();
+    expect(() => plugin.activate()).not.toThrow();
+    expect(() => plugin.deactivate()).not.toThrow();
+  });
+
+  test('getManifest returns null by default', () => {
+    const plugin = new PluginAPI();
+    expect(plugin.getManifest()).toBeNull();
+  });
+
+  test('subclass can override init', () => {
+    let called = false;
+    class MyPlugin extends PluginAPI {
+      init(context) {
+        called = true;
+        this.context = context;
+      }
+    }
+    const p = new MyPlugin();
+    p.init({ foo: 'bar' });
+    expect(called).toBe(true);
+    expect(p.context.foo).toBe('bar');
+  });
+});

tests/plugin-context.test.js

@@ -0,0 +1,79 @@
+const { PluginContext } = require('../src/plugins/plugin-context');
+const { EventBus } = require('../src/plugins/event-bus');
+
+describe('PluginContext', () => {
+  let context;
+  let mockDeps;
+
+  beforeEach(() => {
+    mockDeps = {
+      pluginId: 'test-plugin',
+      sidebar: { registerPanel: jest.fn() },
+      commands: { register: jest.fn() },
+      statusBar: { registerIndicator: jest.fn() },
+      eventBus: new EventBus(),
+      settings: { get: jest.fn(), set: jest.fn(), onChanged: jest.fn() },
+      editor: { getContent: jest.fn(), getSelection: jest.fn(), insertAtCursor: jest.fn(), onContentChanged: jest.fn() },
+      ipc: { invoke: jest.fn(), on: jest.fn() },
+      exportHooks: { preHooks: [], postHooks: [] }
+    };
+    context = new PluginContext(mockDeps);
+  });
+
+  test('exposes sidebar.registerPanel with namespaced id', () => {
+    const handler = jest.fn();
+    context.sidebar.registerPanel('my-panel', { icon: 'test', title: 'Test', render: handler });
+    expect(mockDeps.sidebar.registerPanel).toHaveBeenCalledWith('test-plugin:my-panel', { icon: 'test', title: 'Test', render: handler });
+  });
+
+  test('exposes commands.register with crash-safe wrapper', () => {
+    const badHandler = () => { throw new Error('boom'); };
+    context.commands.register('bad-cmd', 'Bad', badHandler, 'Ctrl+Alt+T');
+    const registeredHandler = mockDeps.commands.register.mock.calls[0][2];
+    expect(() => registeredHandler()).not.toThrow();
+  });
+
+  test('exposes settings.get/set scoped to plugin', () => {
+    context.settings.get('myKey');
+    context.settings.set('myKey', 'myValue');
+    expect(mockDeps.settings.get).toHaveBeenCalledWith('plugins.test-plugin.myKey');
+    expect(mockDeps.settings.set).toHaveBeenCalledWith('plugins.test-plugin.myKey', 'myValue');
+  });
+
+  test('exposes editor methods', () => {
+    context.editor.getContent();
+    context.editor.getSelection();
+    expect(mockDeps.editor.getContent).toHaveBeenCalled();
+    expect(mockDeps.editor.getSelection).toHaveBeenCalled();
+  });
+
+  test('exposes events via event bus', () => {
+    const handler = jest.fn();
+    context.events.on('test:event', handler);
+    context.events.emit('test:event', { data: 1 });
+    expect(handler).toHaveBeenCalledWith({ data: 1 });
+  });
+
+  test('exposes events.hasHandler', () => {
+    expect(context.events.hasHandler('no:such')).toBe(false);
+    context.events.on('exists:event', () => {});
+    expect(context.events.hasHandler('exists:event')).toBe(true);
+  });
+
+  test('exposes ipc.invoke', () => {
+    context.ipc.invoke('test:channel', { a: 1 });
+    expect(mockDeps.ipc.invoke).toHaveBeenCalledWith('test:channel', { a: 1 });
+  });
+
+  test('exposes exports.registerPreHook', () => {
+    const handler = jest.fn();
+    context.exports.registerPreHook(handler);
+    expect(mockDeps.exportHooks.preHooks).toContain(handler);
+  });
+
+  test('exposes exports.registerPostHook', () => {
+    const handler = jest.fn();
+    context.exports.registerPostHook(handler);
+    expect(mockDeps.exportHooks.postHooks).toContain(handler);
+  });
+});

tests/plugin-loader.test.js

@@ -0,0 +1,102 @@
+const path = require('path');
+const fs = require('fs');
+const os = require('os');
+const { PluginLoader } = require('../src/plugins/plugin-loader');
+
+describe('PluginLoader', () => {
+  let tempDir;
+
+  beforeEach(() => {
+    tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'plugin-test-'));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tempDir, { recursive: true, force: true });
+  });
+
+  function writeManifest(dir, manifest) {
+    fs.mkdirSync(dir, { recursive: true });
+    fs.writeFileSync(path.join(dir, 'manifest.json'), JSON.stringify(manifest, null, 2));
+  }
+
+  test('discoverPlugins — finds manifests in built-in directory', () => {
+    const pluginDir = path.join(tempDir, 'my-plugin');
+    writeManifest(pluginDir, {
+      id: 'my-plugin',
+      name: 'My Plugin',
+      version: '1.0.0',
+      description: 'Test'
+    });
+    const loader = new PluginLoader([tempDir]);
+    const plugins = loader.discoverPlugins();
+    expect(plugins).toHaveLength(1);
+    expect(plugins[0].id).toBe('my-plugin');
+  });
+
+  test('discoverPlugins — skips directories without manifest.json', () => {
+    const emptyDir = path.join(tempDir, 'no-manifest');
+    fs.mkdirSync(emptyDir, { recursive: true });
+    const loader = new PluginLoader([emptyDir]);
+    const plugins = loader.discoverPlugins();
+    expect(plugins).toHaveLength(0);
+  });
+
+  test('validateManifest — accepts valid manifest', () => {
+    const manifest = {
+      id: 'test-plugin',
+      name: 'Test Plugin',
+      version: '1.0.0',
+      description: 'A test plugin'
+    };
+    const loader = new PluginLoader([]);
+    expect(loader.validateManifest(manifest)).toBe(true);
+  });
+
+  test('validateManifest — rejects manifest missing id', () => {
+    const manifest = { name: 'No ID', version: '1.0.0', description: 'x' };
+    const loader = new PluginLoader([]);
+    expect(() => loader.validateManifest(manifest)).toThrow(/id/);
+  });
+
+  test('validateManifest — rejects manifest missing name', () => {
+    const manifest = { id: 'test', version: '1.0.0', description: 'x' };
+    const loader = new PluginLoader([]);
+    expect(() => loader.validateManifest(manifest)).toThrow(/name/);
+  });
+
+  test('validateManifest — rejects manifest with duplicate id', () => {
+    const loader = new PluginLoader([]);
+    loader.loadedIds = new Set(['existing-plugin']);
+    expect(() => loader.validateManifest({ id: 'existing-plugin', name: 'Dup', version: '1.0.0', description: 'x' }))
+      .toThrow(/duplicate/i);
+  });
+
+  test('discoverPlugins — loads index.js Plugin export if present', () => {
+    const pluginDir = path.join(tempDir, 'with-index');
+    writeManifest(pluginDir, { id: 'with-index', name: 'With Index', version: '1.0.0', description: 'Test' });
+    // Write a simple index.js with a Plugin export
+    fs.writeFileSync(path.join(pluginDir, 'index.js'), `
+class SimplePlugin { init() {} }
+module.exports = { Plugin: SimplePlugin };
+`);
+    const loader = new PluginLoader([tempDir]);
+    const plugins = loader.discoverPlugins();
+    expect(plugins).toHaveLength(1);
+    expect(plugins[0].PluginClass).toBeDefined();
+    expect(plugins[0].PluginClass.name).toBe('SimplePlugin');
+  });
+
+  test('discoverPlugins — continues if one plugin fails to load', () => {
+    const badDir = path.join(tempDir, 'bad');
+    writeManifest(badDir, { id: 'bad', name: 'Bad', version: '1.0.0', description: 'Broken' });
+    fs.writeFileSync(path.join(badDir, 'index.js'), 'throw new Error("broken");');
+
+    const goodDir = path.join(tempDir, 'good');
+    writeManifest(goodDir, { id: 'good', name: 'Good', version: '1.0.0', description: 'Works' });
+
+    const loader = new PluginLoader([tempDir]);
+    const plugins = loader.discoverPlugins();
+    expect(plugins).toHaveLength(1);
+    expect(plugins[0].id).toBe('good');
+  });
+});

tests/plugin-registry.test.js

@@ -0,0 +1,87 @@
+const { PluginRegistry } = require('../src/plugins/plugin-registry');
+const { PluginAPI } = require('../src/plugins/plugin-api');
+const { EventBus } = require('../src/plugins/event-bus');
+
+class TestPlugin extends PluginAPI {
+  init(context) { this.initialized = true; this.ctx = context; }
+  activate() { this.activated = true; }
+  deactivate() { this.deactivated = true; }
+}
+
+describe('PluginRegistry', () => {
+  let registry;
+  let mockDeps;
+
+  beforeEach(() => {
+    mockDeps = {
+      sidebar: { registerPanel: jest.fn() },
+      commands: { register: jest.fn() },
+      statusBar: { registerIndicator: jest.fn() },
+      eventBus: new EventBus(),
+      settings: { get: jest.fn(), set: jest.fn(), onChanged: jest.fn() },
+      editor: { getContent: jest.fn(() => ''), getSelection: jest.fn(() => ''), insertAtCursor: jest.fn(), onContentChanged: jest.fn() },
+      ipc: { invoke: jest.fn(), on: jest.fn() }
+    };
+    registry = new PluginRegistry(mockDeps);
+  });
+
+  test('register — stores plugin and calls init', () => {
+    registry.register({
+      id: 'test', name: 'Test', version: '1.0.0', description: 'desc',
+      manifest: {}, PluginClass: TestPlugin, dir: '/tmp/test'
+    });
+    const entry = registry.getPlugin('test');
+    expect(entry).toBeDefined();
+    expect(entry.instance.initialized).toBe(true);
+  });
+
+  test('register — works without PluginClass', () => {
+    registry.register({
+      id: 'manifest-only', name: 'Manifest Only', version: '1.0.0', description: 'desc',
+      manifest: {}, PluginClass: null, dir: '/tmp/test'
+    });
+    expect(registry.getPlugin('manifest-only')).toBeDefined();
+  });
+
+  test('register — init error does not crash, plugin not registered', () => {
+    class BadPlugin extends PluginAPI {
+      init() { throw new Error('init fail'); }
+    }
+    expect(() => {
+      registry.register({
+        id: 'bad', name: 'Bad', version: '1.0.0', description: 'desc',
+        manifest: {}, PluginClass: BadPlugin, dir: '/tmp/test'
+      });
+    }).not.toThrow();
+    expect(registry.getPlugin('bad')).toBeUndefined();
+  });
+
+  test('getPlugin — returns undefined for unknown', () => {
+    expect(registry.getPlugin('nope')).toBeUndefined();
+  });
+
+  test('getAll — returns all registered plugins', () => {
+    registry.register({ id: 'a', name: 'A', version: '1', description: '', manifest: {}, PluginClass: null, dir: '' });
+    registry.register({ id: 'b', name: 'B', version: '1', description: '', manifest: {}, PluginClass: null, dir: '' });
+    expect(registry.getAll()).toHaveLength(2);
+  });
+
+  test('activate — calls activate on plugin instance', () => {
+    registry.register({ id: 'test', name: 'Test', version: '1', description: '', manifest: {}, PluginClass: TestPlugin, dir: '' });
+    registry.activate('test');
+    expect(registry.getPlugin('test').instance.activated).toBe(true);
+  });
+
+  test('deactivate — calls deactivate on plugin instance', () => {
+    registry.register({ id: 'test', name: 'Test', version: '1', description: '', manifest: {}, PluginClass: TestPlugin, dir: '' });
+    registry.deactivate('test');
+    expect(registry.getPlugin('test').instance.deactivated).toBe(true);
+  });
+
+  test('exportHooks are available and populated', () => {
+    registry.register({ id: 'test', name: 'Test', version: '1', description: '', manifest: {}, PluginClass: TestPlugin, dir: '' });
+    const handler = jest.fn();
+    registry.getPlugin('test').instance.ctx.exports.registerPreHook(handler);
+    expect(registry.exportHooks.preHooks).toContain(handler);
+  });
+});

tests/project-manager.test.js

@@ -0,0 +1,106 @@
+const { ProjectManager } = require('../src/plugins/built-in/writing-studio/project-manager');
+
+describe('ProjectManager', () => {
+  let pm;
+  let files;
+
+  beforeEach(() => {
+    files = {};
+    pm = new ProjectManager({
+      readFile: (p) => files[p] || null,
+      writeFile: (p, c) => { files[p] = c; },
+      fileExists: (p) => p in files,
+      listDir: (p) => Object.keys(files).filter(f => f.startsWith(p)).map(f => f.slice(p.length + 1))
+    });
+  });
+
+  test('createProject writes .project.json', () => {
+    const project = pm.createProject('/manuscripts/novel', {
+      title: 'My Novel', type: 'manuscript', targetWords: 80000
+    });
+    expect(project.title).toBe('My Novel');
+    expect(files['/manuscripts/novel/.project.json']).toBeDefined();
+    const parsed = JSON.parse(files['/manuscripts/novel/.project.json']);
+    expect(parsed.target.words).toBe(80000);
+  });
+
+  test('loadProject reads and returns project data', () => {
+    files['/manuscripts/novel/.project.json'] = JSON.stringify({
+      title: 'Test', type: 'manuscript', target: { words: 50000 },
+      chapters: [], metadata: {}
+    });
+    const project = pm.loadProject('/manuscripts/novel');
+    expect(project.title).toBe('Test');
+  });
+
+  test('loadProject returns null if no project file', () => {
+    expect(pm.loadProject('/nonexistent')).toBeNull();
+  });
+
+  test('addChapter appends chapter and saves', () => {
+    files['/manuscripts/novel/.project.json'] = JSON.stringify({
+      title: 'Test', type: 'manuscript', target: { words: 50000 },
+      chapters: [], metadata: {}
+    });
+    pm.addChapter('/manuscripts/novel', { file: '01-chapter.md', title: 'Chapter One', status: 'draft' });
+    const parsed = JSON.parse(files['/manuscripts/novel/.project.json']);
+    expect(parsed.chapters.length).toBe(1);
+    expect(parsed.chapters[0].title).toBe('Chapter One');
+  });
+
+  test('compileManuscript concatenates chapter files', () => {
+    files['/manuscripts/novel/.project.json'] = JSON.stringify({
+      title: 'Test', type: 'manuscript', target: { words: 50000 },
+      chapters: [
+        { file: '01.md', title: 'One', status: 'draft' },
+        { file: '02.md', title: 'Two', status: 'draft' }
+      ], metadata: {}
+    });
+    files['/manuscripts/novel/01.md'] = 'First chapter content.';
+    files['/manuscripts/novel/02.md'] = 'Second chapter content.';
+    const result = pm.compileManuscript('/manuscripts/novel');
+    expect(result).toBe('First chapter content.\n\n---\n\nSecond chapter content.');
+  });
+
+  test('compileManuscript skips missing files', () => {
+    files['/manuscripts/novel/.project.json'] = JSON.stringify({
+      title: 'Test', type: 'manuscript', target: { words: 50000 },
+      chapters: [
+        { file: '01.md', title: 'One', status: 'draft' },
+        { file: '02.md', title: 'Two', status: 'draft' }
+      ], metadata: {}
+    });
+    files['/manuscripts/novel/01.md'] = 'Only chapter one.';
+    const result = pm.compileManuscript('/manuscripts/novel');
+    expect(result).toBe('Only chapter one.');
+  });
+
+  test('getStats returns total word count across chapters', () => {
+    files['/manuscripts/novel/.project.json'] = JSON.stringify({
+      title: 'Test', type: 'manuscript', target: { words: 50000 },
+      chapters: [
+        { file: '01.md', title: 'One', status: 'draft' },
+        { file: '02.md', title: 'Two', status: 'draft' }
+      ], metadata: {}
+    });
+    files['/manuscripts/novel/01.md'] = 'word '.repeat(100).trim();
+    files['/manuscripts/novel/02.md'] = 'more '.repeat(50).trim();
+    const stats = pm.getStats('/manuscripts/novel');
+    expect(stats.totalWords).toBeGreaterThan(0);
+    expect(stats.chapterCount).toBe(2);
+    expect(stats.targetWords).toBe(50000);
+    expect(stats.pctComplete).toBeDefined();
+  });
+
+  test('updateChapter modifies a chapter by index', () => {
+    files['/manuscripts/novel/.project.json'] = JSON.stringify({
+      title: 'Test', type: 'manuscript', target: { words: 50000 },
+      chapters: [{ file: '01.md', title: 'Old Title', status: 'draft' }],
+      metadata: {}
+    });
+    pm.updateChapter('/manuscripts/novel', 0, { title: 'New Title', status: 'revised' });
+    const parsed = JSON.parse(files['/manuscripts/novel/.project.json']);
+    expect(parsed.chapters[0].title).toBe('New Title');
+    expect(parsed.chapters[0].status).toBe('revised');
+  });
+});

tests/security-path-handling.test.js

@@ -0,0 +1,114 @@
+/**
+ * Security: Path Traversal Prevention Test Suite
+ * @version 4.3.0
+ */
+
+const path = require('path');
+
+describe('Security: Path Handling', () => {
+  describe('path traversal prevention', () => {
+    it('should detect path traversal patterns', () => {
+      const maliciousPaths = [
+        '../etc/passwd',
+        '../../sensitive',
+        './../outside'
+      ];
+
+      maliciousPaths.forEach(pathStr => {
+        // Path traversal attempts contain .. patterns
+        expect(pathStr).toMatch(/\.\./);
+      });
+    });
+
+    it('should normalize relative paths safely', () => {
+      const safePaths = [
+        './documents/file.md',
+        'relative/path/file.txt'
+      ];
+
+      safePaths.forEach(pathStr => {
+        const normalized = path.normalize(pathStr);
+        // Safe relative paths should normalize cleanly
+        expect(normalized).toBeDefined();
+        expect(typeof normalized).toBe('string');
+      });
+    });
+
+    it('should detect absolute paths', () => {
+      const absolutePath = '/etc/passwd';
+      const isAbsolute = path.isAbsolute(absolutePath);
+      
+      // Linux/Mac: /path is absolute
+      if (process.platform !== 'win32') {
+        expect(isAbsolute).toBe(true);
+      }
+    });
+
+    it('should safely join paths with base directory', () => {
+      const baseDir = '/safe/base/directory';
+      const userInput = 'documents/file.md';
+      
+      const joined = path.join(baseDir, userInput);
+      
+      // Result should contain the safe base
+      expect(joined).toContain('base');
+      expect(joined).toContain('documents');
+    });
+  });
+
+  describe('filename safety', () => {
+    it('should identify safe filenames', () => {
+      const safeNames = [
+        'document.md',
+        'my-file.txt',
+        'file_name.pdf',
+        'report_2026_04_24.xlsx'
+      ];
+
+      safeNames.forEach(name => {
+        // Safe names should not contain path separators or null bytes
+        const isSafe = !/[\\/\0]/.test(name) && name.length > 0;
+        expect(isSafe).toBe(true);
+      });
+    });
+
+    it('should flag filenames with path separators', () => {
+      const problematicNames = [
+        'file/with/slashes.txt',
+        'file\\with\\backslashes.txt'
+      ];
+
+      problematicNames.forEach(name => {
+        // These contain path separators and should be flagged
+        const hasPathSeparators = /[\\/]/.test(name);
+        expect(hasPathSeparators).toBe(true);
+      });
+    });
+
+    it('should enforce minimum filename length', () => {
+      const emptyName = '';
+      
+      expect(emptyName.length).toBe(0);
+      expect(emptyName.length > 0).toBe(false);
+    });
+  });
+
+  describe('validation patterns', () => {
+    it('should validate path existence check pattern', () => {
+      const validationPattern = /^[a-zA-Z0-9._\-/]+$/;
+      
+      const validPaths = ['documents/file.md', 'folder_2026/data.csv'];
+      validPaths.forEach(pathStr => {
+        // These should match a reasonable filename pattern
+        expect(typeof pathStr).toBe('string');
+      });
+    });
+
+    it('should prevent null byte injection', () => {
+      const pathWithNullByte = 'file.txt\0.exe';
+      
+      const isSafe = !pathWithNullByte.includes('\0');
+      expect(isSafe).toBe(false); // Has null byte, not safe
+    });
+  });
+});

tests/settings-store.test.js

@@ -0,0 +1,34 @@
+const { SettingsStore } = require('../src/plugins/settings-store');
+
+describe('SettingsStore', () => {
+  let store;
+  let data;
+
+  beforeEach(() => {
+    data = {};
+    store = new SettingsStore({
+      get: (key) => data[key],
+      set: (key, value) => { data[key] = value; }
+    });
+  });
+
+  test('get returns value for full key', () => {
+    data['plugins.my-plugin.myKey'] = 'myValue';
+    expect(store.get('plugins.my-plugin.myKey')).toBe('myValue');
+  });
+
+  test('get returns undefined for missing key', () => {
+    expect(store.get('plugins.my-plugin.missing')).toBeUndefined();
+  });
+
+  test('set stores value', () => {
+    store.set('plugins.my-plugin.myKey', 42);
+    expect(data['plugins.my-plugin.myKey']).toBe(42);
+  });
+
+  test('set overwrites existing value', () => {
+    data['plugins.my-plugin.myKey'] = 'old';
+    store.set('plugins.my-plugin.myKey', 'new');
+    expect(data['plugins.my-plugin.myKey']).toBe('new');
+  });
+});

tests/snapshot-manager.test.js

@@ -0,0 +1,73 @@
+const { SnapshotManager } = require('../src/plugins/built-in/writing-studio/snapshot-manager');
+
+describe('SnapshotManager', () => {
+  let manager;
+  let store;
+
+  beforeEach(() => {
+    store = {};
+    manager = new SnapshotManager({
+      get: (key) => store[key],
+      set: (key, value) => { store[key] = value; }
+    });
+  });
+
+  test('create stores snapshot with timestamp, content, wordCount', () => {
+    const snap = manager.create('Hello world this is a test', 'auto');
+    expect(snap).toHaveProperty('id');
+    expect(snap.content).toBe('Hello world this is a test');
+    expect(snap.wordCount).toBe(6);
+    expect(snap.label).toBe('auto');
+  });
+
+  test('list returns snapshots ordered newest first', () => {
+    manager.create('first', 'auto');
+    manager.create('second', 'auto');
+    const list = manager.list();
+    expect(list.length).toBe(2);
+    expect(list[0].content).toBe('second');
+  });
+
+  test('getById returns specific snapshot', () => {
+    const snap = manager.create('find me', 'manual');
+    const found = manager.getById(snap.id);
+    expect(found.content).toBe('find me');
+  });
+
+  test('getById returns null for missing id', () => {
+    expect(manager.getById('nope')).toBeNull();
+  });
+
+  test('restore returns content of snapshot', () => {
+    const snap = manager.create('restore this', 'manual');
+    expect(manager.restore(snap.id)).toBe('restore this');
+  });
+
+  test('restore throws for missing snapshot', () => {
+    expect(() => manager.restore('nope')).toThrow('Snapshot not found');
+  });
+
+  test('delete removes a snapshot', () => {
+    const snap = manager.create('delete me', 'auto');
+    manager.delete(snap.id);
+    expect(manager.getById(snap.id)).toBeNull();
+  });
+
+  test('diff returns added/removed line counts', () => {
+    const snap = manager.create('line one\nline two\nline three', 'auto');
+    const result = manager.diff(snap.id, 'line one\nline modified\nline three\nline four');
+    expect(result.added).toBe(2);
+    expect(result.removed).toBe(1);
+  });
+
+  test('diff throws for missing snapshot', () => {
+    expect(() => manager.diff('nope', 'new content')).toThrow('Snapshot not found');
+  });
+
+  test('prune keeps only the N most recent snapshots', () => {
+    for (let i = 0; i < 10; i++) manager.create('snap ' + i, 'auto');
+    manager.prune(5);
+    expect(manager.list().length).toBe(5);
+    expect(manager.list()[0].content).toBe('snap 9');
+  });
+});

tests/sprint-engine.test.js

@@ -0,0 +1,63 @@
+const { SprintEngine } = require('../src/plugins/built-in/writing-studio/sprint-engine');
+
+describe('SprintEngine', () => {
+  let engine;
+  let events;
+
+  beforeEach(() => {
+    events = [];
+    engine = new SprintEngine({
+      onEvent: (name, data) => events.push({ name, data })
+    });
+  });
+
+  test('starts a sprint with duration and initial word count', () => {
+    engine.start(25, 100);
+    expect(engine.isActive()).toBe(true);
+    expect(engine.getRemaining()).toBeLessThanOrEqual(25 * 60 * 1000);
+  });
+
+  test('start throws if sprint already active', () => {
+    engine.start(25, 100);
+    expect(() => engine.start(10, 50)).toThrow('Sprint already active');
+  });
+
+  test('stop calculates WPM from word delta', () => {
+    engine.start(25, 100);
+    const result = engine.stop(350); // 250 words added
+    expect(result.wordDelta).toBe(250);
+    expect(engine.isActive()).toBe(false);
+  });
+
+  test('stop throws if no active sprint', () => {
+    expect(() => engine.stop(100)).toThrow('No active sprint');
+  });
+
+  test('tick emits progress event with remaining time', () => {
+    engine.start(25, 100);
+    engine.tick(200);
+    expect(events.length).toBe(1);
+    expect(events[0].name).toBe('sprint:tick');
+    expect(events[0].data.remaining).toBeDefined();
+    expect(events[0].data.elapsed).toBe(200);
+  });
+
+  test('tick auto-stops when time expires and emits sprint:complete', () => {
+    engine.start(1, 100); // 1 minute
+    engine.tick(60 * 1000 + 1); // just past
+    expect(events.some(e => e.name === 'sprint:complete')).toBe(true);
+    expect(engine.isActive()).toBe(false);
+  });
+
+  test('getRemaining returns 0 when no sprint active', () => {
+    expect(engine.getRemaining()).toBe(0);
+  });
+
+  test('getStats returns elapsed, WPM, wordDelta after stop', () => {
+    engine.start(25, 100);
+    const result = engine.stop(350);
+    expect(result).toHaveProperty('wordDelta', 250);
+    expect(result).toHaveProperty('elapsed');
+    expect(result).toHaveProperty('wpm');
+  });
+});