feat(storage): implement storage manager for centralized management and cleanup

- Added a new Storage Manager component to handle storage statistics, project cleanup, and configuration for CCW centralized storage.
- Introduced functions to calculate directory sizes, get project storage stats, and clean specific or all storage.
- Enhanced SQLiteStore with a public API for executing queries securely.
- Updated tests to utilize the new execute_query method and validate storage management functionalities.
- Improved performance by implementing connection pooling with idle timeout management in SQLiteStore.
- Added new fields (token_count, symbol_type) to the symbols table and adjusted related insertions.
- Enhanced error handling and logging for storage operations.

codex-lens/src/codexlens/errors.py

@@ -16,7 +16,38 @@ class ParseError(CodexLensError):
 
 
 class StorageError(CodexLensError):
-    """Raised when reading/writing index storage fails."""
+    """Raised when reading/writing index storage fails.
+
+    Attributes:
+        message: Human-readable error description
+        db_path: Path to the database file (if applicable)
+        operation: The operation that failed (e.g., 'query', 'initialize', 'migrate')
+        details: Additional context for debugging
+    """
+
+    def __init__(
+        self,
+        message: str,
+        db_path: str | None = None,
+        operation: str | None = None,
+        details: dict | None = None
+    ) -> None:
+        super().__init__(message)
+        self.message = message
+        self.db_path = db_path
+        self.operation = operation
+        self.details = details or {}
+
+    def __str__(self) -> str:
+        parts = [self.message]
+        if self.db_path:
+            parts.append(f"[db: {self.db_path}]")
+        if self.operation:
+            parts.append(f"[op: {self.operation}]")
+        if self.details:
+            detail_str = ", ".join(f"{k}={v}" for k, v in self.details.items())
+            parts.append(f"[{detail_str}]")
+        return " ".join(parts)
 
 
 class SearchError(CodexLensError):