- Add Cloudflare Turnstile integration for login and registration forms
- Create turnstile verification utility with server-side token validation
- Add turnstile_site_key and turnstile_secret_key fields to nodes table
- Implement admin panel UI for configuring Turnstile keys in settings
- Update login and register API routes to verify Turnstile tokens
- Expose turnstile_site_key via GET /api/node endpoint for frontend
- Add admin endpoint to save and update Turnstile configuration
- Create remote_likes and remote_reposts tables for federated interaction tracking
- Add swarm reply metadata fields (swarm_reply_to_id, swarm_reply_to_content, swarm_reply_to_author) to posts table
- Add comprehensive TURNSTILE_SETUP.md documentation with setup instructions and security notes
- Create database migration 0007 with schema updates and indexes
- Protects against bot registrations and automated attacks on federated nodes