fix: add specTitles to cached response mock in test

The test_filter_cached test was failing because the MagicMock
didn't have specTitles defined, causing a validation error
when FastAPI tried to serialize the response.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: MarkusNeusinger

tests/unit/api/test_routers.py

@@ -840,6 +840,7 @@ def test_filter_cached(self, client: TestClient) -> None:
         cached_response.counts = {}
         cached_response.globalCounts = {}
         cached_response.orCounts = []
+        cached_response.specTitles = {}
 
         with (
             patch(DB_CONFIG_PATCH, return_value=True),