The frontend router navigates to /instances/:instanceId/terminal without
project_id or repo_id. The backend terminal REST endpoints were requiring
these path params, causing 404s.
- Simplify _get_terminal_instance to validate by instance_id only
- Update all REST routes from /projects/{pid}/repositories/{rid}/instances/{iid}/terminal/*
to /instances/{instance_id}/terminal/*
- Update frontend API client to match new paths
- Update useTerminalSessions hook to take instanceId only
- Update TerminalPage to use simplified hook
- Update tests to match new paths
Fixes: 404 on GET /projects/repositories/instances/{id}/terminal/sessions
- 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)
alex