feat: Add rich text formatting to sermon notes

Implement comprehensive rich text editing capabilities using Tiptap editor with full formatting toolbar and functionality.

Features:
- Bold, italic, underline, strikethrough text formatting
- Highlight text with yellow marker
- Bullet and numbered lists
- Heading styles (H2, H3)
- Text alignment (left, center, right)
- Undo/redo support
- Clear formatting option
- Intuitive toolbar with icons and tooltips
- Responsive font size support

Technical changes:
- Added Tiptap dependencies to package.json (@tiptap/vue-3, starter-kit, extensions)
- Created RichTextEditor component with full toolbar and formatting options
- Integrated editor into sermon notes section replacing textarea
- Updated download API to convert HTML to formatted plain text
- Updated email API to handle HTML content properly
- Notes now stored as HTML with rich formatting preserved

The editor provides a professional writing experience with all standard formatting tools while maintaining automatic save functionality and seamless integration with email/download features.

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

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

package.json

@@ -11,6 +11,11 @@
     "postinstall": "nuxt prepare"
   },
   "dependencies": {
+    "@tiptap/extension-highlight": "^2.10.3",
+    "@tiptap/extension-text-align": "^2.10.3",
+    "@tiptap/extension-underline": "^2.10.3",
+    "@tiptap/starter-kit": "^2.10.3",
+    "@tiptap/vue-3": "^2.10.3",
     "bcrypt": "^5.1.1",
     "better-sqlite3": "^11.3.0",
     "nodemailer": "^6.9.7",