test(spawn_interception_v2): mock send_result not send (Phase 2.18, pre-empts Phase 1.3 regression)

Phase 1.3 migrated run_worker_lifecycle to send_result(). The mock_ai_client
fixture in test_spawn_interception_v2.py mocked src.ai_client.send and
returned a string. The test_run_worker_lifecycle_approved test asserts
on the call_args (user_message + md_content), which still works with
the new mock name.

Changes:
- Replace patch(src.ai_client.send) with patch(src.ai_client.send_result)
- Rename mock_send to mock_send_result
- Wrap mock return_value with Result(data="Task completed")
- Add "from src.result_types import Result" import

All 3 tests in test_spawn_interception_v2.py pass.

tests/test_spawn_interception_v2.py

@@ -3,6 +3,7 @@ from unittest.mock import MagicMock, patch
 from src import multi_agent_conductor
 from src.models import Ticket, WorkerContext
 from src import events
+from src.result_types import Result
 import threading
 from typing import Generator
 
@@ -19,9 +20,9 @@ class MockDialog:
 
 @pytest.fixture
 def mock_ai_client() -> Generator[MagicMock, None, None]:
- with patch("src.ai_client.send") as mock_send:
-  mock_send.return_value = "Task completed"
-  yield mock_send
+ with patch("src.ai_client.send_result") as mock_send_result:
+  mock_send_result.return_value = Result(data="Task completed")
+  yield mock_send_result
 
 def test_confirm_spawn_pushed_to_queue() -> None:
  event_queue = events.SyncEventQueue()