Add help view and core memory styles

- Introduced styles for the help view including tab transitions, accordion animations, search highlighting, and responsive design.
- Implemented core memory styles with modal base styles, memory card designs, and knowledge graph visualization.
- Enhanced dark mode support across various components.
- Added loading states and empty state designs for better user experience.

codex-lens/tests/test_entities.py

@@ -203,6 +203,7 @@ class TestEntitySerialization:
             "name": "test",
             "kind": "function",
             "range": (1, 10),
+            "file": None,
             "token_count": None,
             "symbol_type": None,
         }