- Add core Middleware support via `core.Default.Use()`
- Implement download command handlers for YouTube, Instagram, TikTok, and Facebook
- Add regex-based URL validation for all download commands
- Add API client for fetching download links
- Add helpers for uploading and sending media to WhatsApp
Co-Authored-By: Claude Opus 4.7 <[email protected]>
Core framework (Handler, Command, Default muxer) in core/ package.
Command self-registration via init() with blank imports in cmds/.
Context helpers (send, reply, download, upload) in context/ package.
Permission system with GROUP_ONLY / PRIVATE_ONLY checks.
WhatsApp client configured as Safari with history sync disabled.