P0 foundation for AgentHub Social: schema, CRUD routes, and tests.
- Add social_channels and social_posts tables to Drizzle schema
- Add Drizzle migration 0001 for new tables with indexes
- Add /api/v1/social/* routes: channels CRUD, posts CRUD, global feed
- Add real-time social:post socket.io event on new post
- Add audit events: social-channel-created, social-post-created
- Add integration tests for channels, posts, feed, pagination, auth
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
