Add print functionality and native PDF support (v1.7.7)

- Added Print menu item with Ctrl+P keyboard shortcut for native OS printing
- Implemented print IPC handlers in main and renderer processes
- Remapped Toggle Preview from Ctrl+P to Ctrl+Shift+P to avoid conflicts
- Added PDFKit (v0.14.0) for native PDF generation without Pandoc
- Added html2pdf.js (v0.10.1) for HTML to PDF conversion
- Enhanced CLAUDE.md with new v1.7.7 feature documentation
- Print supports cross-platform printing (Windows, macOS, Linux)

Features:
- Native print dialog with background color printing
- Professional PDF export without system dependencies
- Improved portability and offline support

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/main.js

@@ -199,6 +199,12 @@ function createMenu() {
           click: saveAsFile
         },
         { type: 'separator' },
+        {
+          label: 'Print',
+          accelerator: 'CmdOrCtrl+P',
+          click: () => mainWindow.webContents.send('print-document')
+        },
+        { type: 'separator' },
         {
           label: 'Recent Files',
           submenu: buildRecentFilesMenu()
@@ -265,7 +271,7 @@ function createMenu() {
       submenu: [
         {
           label: 'Toggle Preview',
-          accelerator: 'CmdOrCtrl+P',
+          accelerator: 'CmdOrCtrl+Shift+P',
           click: () => mainWindow.webContents.send('toggle-preview')
         },
         {
@@ -1151,6 +1157,19 @@ ipcMain.on('set-current-file', (event, filePath) => {
   currentFile = filePath;
 });
 
+// Handle print document
+ipcMain.on('print-document', (event) => {
+  if (mainWindow) {
+    // Open native print dialog
+    mainWindow.webContents.print({
+      silent: false,
+      printBackground: true,
+      color: true,
+      margin: { marginType: 'default' }
+    });
+  }
+});
+
 // Handle renderer ready for file association
 ipcMain.on('renderer-ready', (event) => {
   rendererReady = true;