Fix content script connection issues with comprehensive fallback system

- Add robust error handling for content script communication failures
- Implement automatic content script injection when not available
- Add executeScript fallback when message passing fails
- Update manifest.json to use http/https patterns instead of <all_urls>
- Add comprehensive debugging logs to troubleshoot connection issues
- Ensure MetaMask detection works on all websites with multiple fallback methods
- Handle cases where content scripts can't run (chrome:// pages, etc.)