Add comprehensive tests for schema cleanup migration and search comparison

- Implement tests for migration 005 to verify removal of deprecated fields in the database schema.
- Ensure that new databases are created with a clean schema.
- Validate that keywords are correctly extracted from the normalized file_keywords table.
- Test symbol insertion without deprecated fields and subdir operations without direct_files.
- Create a detailed search comparison test to evaluate vector search vs hybrid search performance.
- Add a script for reindexing projects to extract code relationships and verify GraphAnalyzer functionality.
- Include a test script to check TreeSitter parser availability and relationship extraction from sample files.

codex-lens/src/codexlens/entities.py

@@ -13,6 +13,7 @@ class Symbol(BaseModel):
     name: str = Field(..., min_length=1)
     kind: str = Field(..., min_length=1)
     range: Tuple[int, int] = Field(..., description="(start_line, end_line), 1-based inclusive")
+    file: Optional[str] = Field(default=None, description="Full path to the file containing this symbol")
     token_count: Optional[int] = Field(default=None, description="Token count for symbol content")
     symbol_type: Optional[str] = Field(default=None, description="Extended symbol type for filtering")