- Implement three-pane Xcode-style layout with toggleable sidebars
- Refactor into modular components for better maintainability
- Replace tabbed interface with iMessage-style message bubbles
- Redesign audio player for 70% height reduction with horizontal layout
- Update to native macOS colors and remove custom backgrounds
- Increase minimum window size to 1000x700 for better usability
- Pass WhisperState to HistoryWindowController for transcription services
- Update MenuBarManager to store and pass WhisperState reference
- Ensure all transcription providers work in separate history window
- Add HistoryWindowController for native macOS window management
- Update MenuBarManager to support window opening
- Modify sidebar to open history in separate window instead of inline
- Update navigation handlers to use window controller
- Settings remains inline as before
