Update documentation for post editing functionality

- Added post editing feature to README.md features list
- Documented keyboard shortcuts: Ctrl+Shift+E (edit) and Shift+Delete (delete)
- Added post editing to CLAUDE.md completed features section
- Updated keyboard shortcuts section in both documentation files
- Clarified that editing only works for user's own posts

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

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

CLAUDE.md

@@ -429,6 +429,8 @@ Due to Qt's visual display synchronization, thread collapse may require double-o
 - **Ctrl+F**: Favorite selected post
 - **Ctrl+C**: Copy selected post to clipboard
 - **Ctrl+U**: Open URLs from selected post in browser
+- **Ctrl+Shift+E**: Edit selected post (your own posts only)
+- **Shift+Delete**: Delete selected post (your own posts only)
 - **F5**: Refresh timeline
 - **Ctrl+,**: Settings
 - **Escape**: Close dialogs
@@ -548,6 +550,7 @@ verbose_announcements = true
 - **Poll Voting**: ✅ Accessible poll interaction with keyboard navigation
 - **User Profile Viewer**: ✅ Comprehensive profile dialog with bio, fields, recent posts
 - **Social Actions**: ✅ Follow/unfollow, block/unblock, mute/unmute from profile viewer
+- **Post Editing**: ✅ Edit your own posts and DMs with proper local/federated ownership detection
 
 ### Remaining High Priority Features
 - **User Blocking Management**: Block/unblock users with dedicated management interface
@@ -724,4 +727,5 @@ content_text.setTextInteractionFlags(Qt.TextSelectableByKeyboard | Qt.TextSelect
 This document serves as the comprehensive development guide for Bifrost, ensuring all accessibility, functionality, and architectural decisions are preserved and can be 
 referenced throughout development.
 
-- When adding or adjusting features be extremely thorough. Make sure every aspect of the code having to do with the feature or fix is completely updated.
+- When adding or adjusting features be extremely thorough. Make sure every aspect of the code having to do with the feature or fix is completely updated.
+- Always update documentation especially if anything such as keybindings changes.