fix(types): resolve pre-existing basedpyright errors in tests

Fix ~790 basedpyright errors across the test suite:
- Type stub subclasses of real production classes with super().__init__()
- Add missing generic type arguments and Dict[str, Any] annotations
- Add None guards before subscript/member access
- Adapt tests to production API changes (removed dead handlers,
  PersistentModelCache.get_default, _i18n_filter_added location)

tests/routes/test_randomizer_endpoints.py

@@ -31,7 +31,7 @@ class StubLoraService:
 @pytest.fixture
 def routes():
     handler = LoraRoutes()
-    handler.service = StubLoraService()
+    handler.service = StubLoraService()  # pyright: ignore[reportAttributeAccessIssue]
     return handler