fix: Apply final formatting fixes for pre-commit hooks

- Remove unused imports (asyncio, pathlib.Path)
- Remove unused class imports in demo script
- Ensure all files pass ruff format and pre-commit checks

This should resolve all remaining CI linting issues.

apps/twitter_rag.py

@@ -11,7 +11,6 @@ Usage:
 
 import argparse
 import asyncio
-from pathlib import Path
 
 from apps.base_rag_example import BaseRAGExample
 from apps.twitter_data.twitter_mcp_reader import TwitterMCPReader