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/nodes/test_nunchaku_lora.py

@@ -31,7 +31,7 @@ class _DummyModel:
         return self
 
 def test_nunchaku_load_lora_legacy_fallback(monkeypatch, caplog):
-    import folder_paths
+    import folder_paths  # pyright: ignore[reportMissingImports]
     import copy
     
     dummy_model = _DummyModel()
@@ -59,7 +59,7 @@ def test_nunchaku_load_lora_legacy_fallback(monkeypatch, caplog):
     assert result_model.model.diffusion_model.loras[0][1] == 0.8
 
 def test_nunchaku_load_lora_new_logic(monkeypatch):
-    import folder_paths
+    import folder_paths  # pyright: ignore[reportMissingImports]
     import os
     
     dummy_model = _DummyModel()