- Added Textual TUI framework with modern terminal UI
- Created main TUI app with navigation, message view, event log, state inspector
- Added comprehensive CSS styling for Discord-like appearance
- Implemented navigation pane, message area, event log, state tree, command bar
- Added keyboard shortcuts (Ctrl+Q quit, Ctrl+C command, Ctrl+N/P nav, etc.)
- Integrated TUI with existing REST/Gateway servers and state management
- Added CLI flag --tui/--no-tui to launch TUI mode
- Added Textual and textual-dev to optional dependencies
All 19 tests passing.
