fix(retrieval): run in-process when pipes are forbidden

The Codex sandbox on Windows denies the pipes that the daemon and worker
process use, so searches waited 120 seconds and then failed. Detect that and
run the search in-process.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/tests/test-retrieval-server.py

@@ -133,6 +133,13 @@ class RetrievalServerTests(unittest.TestCase):
                 self.assertNotEqual(MODULE.daemon_address(data_dir), old_address)
                 self.assertNotEqual(MODULE.daemon_lock_path(data_dir), old_lock)
 
+    def test_run_direct_runs_in_process_when_pipes_are_forbidden(self):
+        def action(action, root, data_dir, model_cache, query, top_k, output):
+            output.put((True, [query, top_k]))
+
+        with patch.object(MODULE, 'pipes_available', return_value=False), patch.object(MODULE, 'run_action', action):
+            self.assertEqual(MODULE.run_direct('search', Path('.'), Path('.'), Path('.'), 'two words', 3), ['two words', 3])
+
     def test_model_kwargs_use_bfloat16_only_on_supporting_gpus(self):
         bfloat16 = object()
         for available, supported, expected in [(True, True, {'dtype': bfloat16}), (True, False, {}), (False, True, {})]: