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/services/test_model_metadata_provider.py

@@ -6,11 +6,12 @@ from py.services import model_metadata_provider as provider_module
 from py.services.errors import RateLimitError
 from py.services.model_metadata_provider import (
     FallbackMetadataProvider,
+    ModelMetadataProvider,
     RateLimitRetryingProvider,
 )
 
 
-class RateLimitThenSuccessProvider:
+class RateLimitThenSuccessProvider(ModelMetadataProvider):
     def __init__(self) -> None:
         self.calls = 0
 
@@ -20,8 +21,20 @@ class RateLimitThenSuccessProvider:
             raise RateLimitError("limited", retry_after=1.0)
         return {"id": "ok"}, None
 
+    async def get_model_versions(self, model_id: str):
+        return None
 
-class AlwaysRateLimitedProvider:
+    async def get_model_version(self, model_id=None, version_id=None):
+        return None
+
+    async def get_model_version_info(self, version_id: str):
+        return None, None
+
+    async def get_user_models(self, username: str, cursor=None):
+        return None
+
+
+class AlwaysRateLimitedProvider(ModelMetadataProvider):
     def __init__(self) -> None:
         self.calls = 0
 
@@ -29,8 +42,20 @@ class AlwaysRateLimitedProvider:
         self.calls += 1
         raise RateLimitError("limited")
 
+    async def get_model_versions(self, model_id: str):
+        return None
 
-class TrackingProvider:
+    async def get_model_version(self, model_id=None, version_id=None):
+        return None
+
+    async def get_model_version_info(self, version_id: str):
+        return None, None
+
+    async def get_user_models(self, username: str, cursor=None):
+        return None
+
+
+class TrackingProvider(ModelMetadataProvider):
     def __init__(self) -> None:
         self.calls = 0
 
@@ -38,6 +63,18 @@ class TrackingProvider:
         self.calls += 1
         return {"id": "secondary"}, None
 
+    async def get_model_versions(self, model_id: str):
+        return None
+
+    async def get_model_version(self, model_id=None, version_id=None):
+        return None
+
+    async def get_model_version_info(self, version_id: str):
+        return None, None
+
+    async def get_user_models(self, username: str, cursor=None):
+        return None
+
 
 @pytest.mark.asyncio
 async def test_fallback_retries_same_provider_on_rate_limit(monkeypatch):