Add comprehensive improvements across REST and gRPC APIs:
- Add structured logging for all notification operations
- Implement HTML email support with multipart/alternative MIME
- Add CC and BCC recipient support for email notifications
- Add GetNotifiers endpoint to query available notifier configurations
- Support configurable From name in SMTP configuration
- Auto-detect content type (text vs HTML) in notification bodies
- Improve error handling and validation across all endpoints
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
igodwin