- Add WebSocket route /ws/tool-instances/{instance_id}/terminal/{session_id}
- Preserve /terminal as default-session alias for backward compatibility
- Extract shared _handle_terminal_websocket handler for both routes
- Add REST endpoints: GET list, POST create, DELETE close, POST reset, POST rename
- Preserve legacy POST .../terminal/reset as default session alias
- Add frontend API client (apps/web/src/api/terminal.ts)
- Add useTerminalSessions React hook for session CRUD + state management
- Add integration tests for auth requirements on all new endpoints
Quality gates: pytest (8 new passed, 182 total passed, 51 pre-existing failures)
