refactor(backend): update API routes and service layer

- Update agent router/service/repository with new endpoints
- Update auth routes with phone-based authentication
- Update users service with new phone lookup
- Update schedule_items with new schemas
- Update message schemas with visibility support
- Update settings with new automation scheduler config
- Update CLI with new commands
- Update tests to match new API contracts

backend/tests/unit/v1/agent/test_owner_guard.py

@@ -10,7 +10,7 @@ from v1.agent.service import ensure_session_owner
 
 
 def test_owner_guard_denies_non_owner() -> None:
-    user = CurrentUser(id=uuid4(), email="self@example.com")
+    user = CurrentUser(id=uuid4(), phone="self@example.com")
 
     with pytest.raises(HTTPException):
         ensure_session_owner(owner_id="other-user", current_user=user)