Add comprehensive user profile viewer with full accessibility support

- Create ProfileDialog with threaded loading and tabbed interface
- Display user bio, profile fields, stats, and recent posts
- Implement Follow/Unfollow, Block/Unblock, Mute/Unmute actions
- Add ActivityPub API methods for social actions and account management
- Enable keyboard navigation in read-only bio text with TextInteractionFlags
- Replace TODO profile viewing with fully functional dialog
- Update documentation to reflect completed profile features

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

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

README.md

@@ -25,6 +25,8 @@ This project was created through "vibe coding" - a collaborative development app
 - **Direct Message Interface**: Dedicated conversation view with threading support
 - **Bookmarks**: Save and view bookmarked posts in a dedicated timeline
 - **Poll Support**: Create, vote in, and view results of fediverse polls with full accessibility
+- **User Profile Viewer**: Comprehensive profile viewing with bio, fields, recent posts, and social actions
+- **Social Features**: Follow/unfollow, block/unblock, and mute/unmute users directly from profiles
 
 ## Audio System