- Add parseSlashCommand() with regex-based parser for /cmd [args] format
- Add CommandRegistry with local-only commands (help, stop, cost, status, clear) and gateway manifest support
- Add short alias resolution: /n→new, /m→model, /t→thinking, /a→agent, /s→status, /h→help, /pref→preferences
- Add executeHelp() and executeStatus() local command handlers
- Extend Message.role union with 'system' for in-TUI system messages
- Handle commands:manifest socket event to update registry from gateway
- Wire InputBar to intercept /commands before sending to socket
- Render system messages as dimmed ⚙ prefix without avatar chrome
- Expose addSystemMessage() and socketRef from useSocket hook
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
