Release v0.1.9: enforce Photos API boundary and finalize Server migration

tests/conftest.py

@@ -30,3 +30,17 @@ def client(app):
 @pytest.fixture
 def service(app):
     return app.state.service
+
+
+@pytest.fixture
+def legacy_photo_engine(monkeypatch):
+    """Exercise retained legacy internals without weakening production policy.
+
+    These fixtures cover rendering, retention and migration algorithms that used
+    filesystem inputs historically. API boundary tests never use this override.
+    """
+    from pigway_frame_flow.providers.photo_sources import PhotoSources
+
+    monkeypatch.setattr(
+        PhotoSources, "require_api_source", staticmethod(lambda source: None)
+    )