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

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

Amit Haridas

CLAUDE.md

@@ -0,0 +1,103 @@
+# CLAUDE.md — MarkdownConverter (master)
+
+> General code-quality, JavaScript, git, security, and testing standards are in the **global CLAUDE.md**. This file holds project- and branch-specific notes.
+
+## Project Overview
+
+Electron desktop app for Markdown editing and universal file conversion powered by Pandoc. Cross-platform (Win/macOS/Linux). Features: multi-tab editor with live preview, 25+ themes, PDF viewer/editor (merge/split/compress/rotate/watermark/password), export to 20+ formats (PDF/DOCX/ODT/EPUB/HTML/LaTeX/RTF/PPTX), batch conversion, syntax highlighting, diagram support (Mermaid), Git integration, and a plugin system.
+
+- **Version:** 4.4.3
+- **License:** MIT
+- **App ID:** `com.concreteinfo.markdownconverter`
+
+## Branch Specifics
+
+This is the **primary/release branch** — a vanilla JavaScript Electron app with no bundler or framework in the renderer. The renderer is a single large `renderer.js` (5,300+ lines) loaded directly via `src/index.html`. All UI is hand-rolled DOM manipulation.
+
+## Architecture
+
+### Main Process (`src/main.js` — 4,260 lines)
+Monolithic main process file. Contains all IPC handlers, Pandoc invocation, file operations, menu definitions (600+ lines), and window lifecycle. Key modules extracted:
+- `src/main/PDFOperations.js` — PDF manipulation via `pdf-lib` (merge, split, compress, rotate, delete, reorder, watermark, encrypt, decrypt, permissions)
+- `src/main/GitOperations.js` — Git status/stage/commit/log via `simple-git`
+
+### Renderer (`src/renderer.js` — 5,361 lines)
+Vanilla JS, no framework. Directly manipulates DOM. Loads CodeMirror 6 via `src/editor/codemirror-setup.js`. Uses `marked` + `highlight.js` + `DOMPurify` + `mermaid` for rendering. Lazy-loads sidebar panels, REPL, command palette, zen mode.
+
+### Preload (`src/preload.js` — 448 lines)
+Exists as IPC bridge, but **`contextIsolation: false` and `nodeIntegration: true`** — the renderer has full Node access. Preload is effectively a thin passthrough.
+
+### Security Model
+- `contextIsolation: false` + `nodeIntegration: true` (legacy; the react-electron branch fixes this)
+- Pandoc invoked via `execFile` (not `exec`) to prevent shell injection
+- Path traversal protection: `validatePath()`, `resolveWritablePath()`, blocks sensitive system dirs
+- Permission handler only allows `clipboard-read`/`clipboard-write`
+- Rate limiter on conversions (2-second minimum interval)
+- File size limit: 50MB
+- Error message sanitization strips absolute paths
+
+### Plugin System (`src/plugins/`)
+Manifest-based discovery (`manifest.json`). Built-in `writing-studio` plugin with sprint/goal/snapshot management. Plugin API exposed via `src/plugins/plugin-api.js`.
+
+### Settings
+Custom JSON file store at `<userData>/settings.json` (NOT `electron-store` despite the dependency). Recent files at `<userData>/recent-files.json`.
+
+## System Dependencies
+
+| Dependency | Required | Notes |
+|---|---|---|
+| **Node.js** | >= 20 | Electron 41 bundles Node 20.x |
+| **Pandoc** | Yes (for exports) | Downloaded to `bin/<platform>/pandoc` via `scripts/download-tools.js` (v3.9.0.2). Falls back to system PATH. Must be present for DOCX/ODT/EPUB/LaTeX/PPTX export. |
+| **FFmpeg** | Bundled | `ffmpeg-static` npm package; `asarUnpacked` for packaged builds |
+| **MiKTeX / TeX Live** | Optional | For LaTeX PDF export; MiKTeX PATH injected on Windows automatically |
+| **ImageMagick** | Optional | Linux image conversion; listed as deb dependency |
+| **LibreOffice** | Optional | Enhanced document conversion; listed as deb dependency |
+
+## Development Commands
+
+```bash
+npm start                  # Launch Electron app (dev mode)
+npm test                   # Jest test suite
+npm test:watch             # Jest in watch mode
+npm test:coverage          # Jest with coverage report
+npm run lint               # ESLint check (src + tests)
+npm run lint:fix           # ESLint auto-fix
+npm run format             # Prettier write
+npm run format:check       # Prettier check only
+npm run download-tools     # Download Pandoc binaries to bin/
+npm run generate-icons     # Generate app icons via sharp
+```
+
+## Build & Package
+
+**Tool:** `electron-builder` (v26.0.12), config inline in `package.json` (no separate config file).
+
+| Target | Platforms |
+|---|---|
+| `npm run build` | electron-builder (default platform) |
+| `npm run build:win` | Windows: NSIS installer + portable + zip (x64) |
+| `npm run build:mac` | macOS: default dmg |
+| `npm run build:linux` | Linux: deb + AppImage + snap |
+| `npm run dist` | Build without publish |
+| `npm run dist:all` | Build for all platforms |
+
+**Bundled with builds:** Pandoc binary per platform. FFmpeg via `ffmpeg-static` (asarUnpacked). NSIS installer uses custom script at `scripts/nsis-installer.nsh`.
+
+**Output:** `dist/` directory.
+
+**CI:** GitHub Actions workflows in `.github/workflows/` (ci.yml, release.yml).
+
+## Project Conventions / Gotchas
+
+- **No bundler/transpilation.** The app uses vanilla CommonJS JavaScript. `src/main.js` is loaded directly by Electron. No webpack, no Vite, no TypeScript, no Babel.
+- **Monolithic files.** `main.js` (4,260 lines) and `renderer.js` (5,361 lines) contain most logic. Not ideal but is the current state of this branch.
+- **CodeMirror 6** for the editor, configured in `src/editor/codemirror-setup.js`.
+- **PDF rendering** uses `pdfjs-dist`; **PDF manipulation** uses `pdf-lib` in the main process.
+- **Renderer security is weak** — full Node access in renderer. Do NOT introduce new privileged renderer code without understanding this.
+- **Pandoc is external.** Must be installed separately or downloaded via `npm run download-tools`. HTML and built-in PDF export work without Pandoc; other formats require it.
+- **PDF export fallback chain:** xelatex -> pdflatex -> lualatex -> Electron built-in `printToPDF()`.
+- **ESLint flat config** (`eslint.config.js`) with ECMAScript 2022. Prettier with 2-space indent, single quotes, semicolons, 100-char width.
+- **Tests:** Jest with jsdom environment, 15% coverage threshold. 24 test files in `tests/`.
+- **File associations:** `.md`, `.markdown`, `.pdf` registered at install.
+- **Single instance lock** enforced via `app.requestSingleInstanceLock()`.
+- **Adapters layer** (`src/adapters/`) abstracts file system operations for potential future non-Electron targets.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "markdown-converter",
-  "version": "4.4.2",
+  "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": {

src/renderer.js

@@ -1,6 +1,6 @@
 /**
  * MarkdownConverter Renderer Process
- * @version 4.4.2
+ * @version 4.4.3
  */
 
 const { ipcRenderer } = require('electron');
@@ -11,15 +11,53 @@ const DOMPurify = createDOMPurify(window);
 const hljs = require('highlight.js');
 const { createEditor } = require('./editor/codemirror-setup');
 const { undo, redo } = require('@codemirror/commands');
+
+// 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;
+let _ModalManager;
 if (typeof window !== 'undefined' && window.ModalManager) {
-    ModalManager = window.ModalManager;
+    _ModalManager = window.ModalManager;
 } else {
     const result = require('./utils/ModalManager');
-    ModalManager = result.ModalManager || result;
+    _ModalManager = result.ModalManager || result;
 }
 // Lazy-loaded modules — defer heavy imports until first use
 let _SidebarManager, _renderTemplatesPanel, _renderExplorerPanel, _renderGitPanel, _renderSnippetsPanel;
@@ -1543,6 +1581,7 @@ let tabManager;
 let replPanel;
 
 document.addEventListener('DOMContentLoaded', async () => {
+    const ModalManager = _ModalManager;
     tabManager = new TabManager();
 
     // Load saved Custom Preview CSS if present
@@ -1675,6 +1714,11 @@ document.addEventListener('DOMContentLoaded', async () => {
     });
 
     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,
@@ -1811,10 +1855,6 @@ document.addEventListener('DOMContentLoaded', async () => {
         }
     });
 
-    // Initialize command palette
-    const CommandPalette = getCommandPalette();
-    const commandPalette = new CommandPalette();
-
     // Initialize print preview
     const PrintPreview = getPrintPreview();
     const printPreview = new PrintPreview();
@@ -2041,6 +2081,8 @@ ipcRenderer.on('redo', () => {
             redo(tab.editorView);
         }
     }
+});
+
 // Custom Preview CSS event handlers and trigger helpers
 function applyCustomPreviewCSS(cssContent) {
     let styleTag = document.getElementById('custom-preview-style');

src/utils/ModalManager.js

@@ -1,6 +1,6 @@
 /**
  * ModalManager - Unified modal system with accessibility support
- * @version 4.4.2
+ * @version 4.4.3
  */
 class ModalManager {
     #modal;