Add comprehensive direct messaging and bookmarks system

- Add dedicated Messages timeline with conversation threading
- Implement bookmarks timeline for saved posts
- Support both standard ActivityPub conversations and Pleroma chats
- Auto-mark conversations as read when selected
- Full pagination support for messages and bookmarks
- Reorder timeline tabs for better UX (Messages now second tab)
- Remove verbose prefixes for cleaner accessibility
- Add conversation management API endpoints
- Maintain accessibility-first design with no text truncation

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

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

README.md

@@ -13,7 +13,7 @@ This project was created through "vibe coding" - a collaborative development app
 - **Full ActivityPub Support**: Compatible with Pleroma, GoToSocial, and other fediverse servers
 - **Screen Reader Optimized**: Designed from the ground up for excellent accessibility
 - **Threaded Conversations**: Navigate complex conversation trees with keyboard shortcuts
-- **Timeline Switching**: Easy navigation between Home, Mentions, Local, and Federated timelines
+- **Timeline Switching**: Easy navigation between Home, Messages, Mentions, Local, Federated, Bookmarks, Followers, and Following timelines
 - **Desktop Notifications**: Cross-platform notifications for mentions, direct messages, and timeline updates
 - **Customizable Audio Feedback**: Rich sound pack system with themed audio notifications
 - **Soundpack Manager**: Secure repository-based soundpack discovery and installation
@@ -22,6 +22,8 @@ This project was created through "vibe coding" - a collaborative development app
 - **Auto-refresh**: Intelligent timeline updates based on user activity
 - **Clean Interface**: Focused on functionality over visual design
 - **Keyboard Navigation**: Complete keyboard control with intuitive shortcuts
+- **Direct Message Interface**: Dedicated conversation view with threading support
+- **Bookmarks**: Save and view bookmarked posts in a dedicated timeline
 
 ## Audio System
 
@@ -57,9 +59,13 @@ Bifrost includes a sophisticated sound system with:
 
 ### Timeline Navigation
 - **Ctrl+1**: Switch to Home timeline
-- **Ctrl+2**: Switch to Mentions/Notifications timeline  
-- **Ctrl+3**: Switch to Local timeline
-- **Ctrl+4**: Switch to Federated timeline
+- **Ctrl+2**: Switch to Messages/DM timeline
+- **Ctrl+3**: Switch to Mentions/Notifications timeline  
+- **Ctrl+4**: Switch to Local timeline
+- **Ctrl+5**: Switch to Federated timeline
+- **Ctrl+6**: Switch to Bookmarks timeline
+- **Ctrl+7**: Switch to Followers timeline
+- **Ctrl+8**: Switch to Following timeline
 - **Ctrl+Tab**: Switch between timeline tabs
 - **F5**: Refresh current timeline