test(context_pruner): wrap send_result lambda in Result(data=...) (Phase 2 follow-up)

The test_token_reduction_logging test in test_context_pruner.py
mocked src.ai_client.send_result with a lambda that returned
a raw string. The production code now does "if not result.ok:"
which fails on raw strings.

1 test passes (was 1 pre-existing failure).

tests/test_context_pruner.py

@@ -4,6 +4,7 @@ from pathlib import Path
 from src.file_cache import ASTParser
 from src.models import Ticket, Track, WorkerContext
 from src.multi_agent_conductor import run_worker_lifecycle
+from src.result_types import Result
 
 def test_targeted_extraction():
  parser = ASTParser("python")
@@ -104,7 +105,7 @@ def test_token_reduction_logging(capsys):
  with pytest.MonkeyPatch().context() as m:
   m.setattr("builtins.open", lambda f, *args, **kwargs: type('obj', (object,), {'read': lambda s: code, '__enter__': lambda s: s, '__exit__': lambda s, *a: None})())
   m.setattr("pathlib.Path.exists", lambda s: True)
-  m.setattr("src.ai_client.send_result", lambda **kwargs: "DONE")
+  m.setattr("src.ai_client.send_result", lambda **kwargs: Result(data="DONE"))
   
   run_worker_lifecycle(ticket, context, context_files=["test.py"])