New Features:
- Add Claude Code plugin marketplace with mail-attachment-analyzer
- Smart attachment analysis with 3 modes (quick/interactive/auto)
- Automatic document classification (invoices, contracts, tax docs)
- Email thread tracking and version evolution detection
- Action item extraction with deadline recognition

Improvements:
- Enhanced README with plugin installation instructions
- Added comprehensive plugin documentation
- Both English and Chinese documentation updated

Installation:
Users can now install Claude Code plugins for intelligent email analysis:
/plugin marketplace add /path/to/mail-mcp-bridge/plugins
/plugin install mail-attachment-analyzer@mail-mcp

Breaking Changes: None