test(ai): stabilize recovery callback contract

apps/api/tests/test_ollama_failover_manager.py

@@ -23,7 +23,7 @@ OllamaFailoverManager 單元測試 - P1.1c v4.0
 from __future__ import annotations
 
 import asyncio
-from unittest.mock import ANY, AsyncMock, MagicMock, patch
+from unittest.mock import ANY, AsyncMock, MagicMock, create_autospec, patch
 
 import pytest
 
@@ -402,7 +402,22 @@ class TestSelectProvider:
             gcp_b_status=HealthStatus.HEALTHY,
             local_status=HealthStatus.OFFLINE,
         )
-        recovery_callback = AsyncMock()
+        async def metadata_callback(
+            provider_name: str,
+            *,
+            observation_generation: int,
+            observation_started_at_monotonic: float,
+        ) -> None:
+            _ = (
+                provider_name,
+                observation_generation,
+                observation_started_at_monotonic,
+            )
+
+        # Bare AsyncMock signature reporting varies across runner Python patch
+        # versions. Autospec the production callback contract so this test
+        # verifies our metadata boundary instead of unittest.mock internals.
+        recovery_callback = create_autospec(metadata_callback)
         manager.set_recovery_callback(recovery_callback)
         audit = AsyncMock()