feat: Enhance navigation and cleanup for graph explorer view

- Added a cleanup function to reset the state when navigating away from the graph explorer.
- Updated navigation logic to call the cleanup function before switching views.
- Improved internationalization by adding new translations for graph-related terms.
- Adjusted icon sizes for better UI consistency in the graph explorer.
- Implemented impact analysis button functionality in the graph explorer.
- Refactored CLI tool configuration to use updated model names.
- Enhanced CLI executor to handle prompts correctly for codex commands.
- Introduced code relationship storage for better visualization in the index tree.
- Added support for parsing Markdown and plain text files in the symbol parser.
- Updated tests to reflect changes in language detection logic.

codex-lens/tests/test_config.py

@@ -195,7 +195,7 @@ class TestConfig:
             try:
                 config = Config()
                 assert config.language_for_path("test.xyz") is None
-                assert config.language_for_path("README.md") is None
+                assert config.language_for_path("data.csv") is None
             finally:
                 del os.environ["CODEXLENS_DATA_DIR"]