* feat: add custom sub-agents with /agents TUI and reliable interrupt
- Custom sub-agents stored in ~/.grok/user-settings.json (name, model, instruction)
- Validation against known model IDs, reserved name protection
- Injected into system prompt and available via task tool in all modes
- /agents TUI modal for browsing, adding, editing, and removing sub-agents
- Custom agent name shown in task UI instead of generic "Sub-agent"
- Foreground bash/search tools now accept abort signals for real cancellation
- Esc interrupt aligned with queue-force path for consistent cancel behavior
* fix issues found in code review
Ismail Pelaseyed
fc37434a2a