This commit adds multiple major features and improvements:
1. Add runtime config API with save/reset capabilities
2. Implement per-room distributor override with global fallback
3. Add user management page and inline user controls
4. Update auth policy with admin/root permissions
5. Refine frontend navigation and error boundary
6. Update static assets and build system
7. Add CDN/SRS/Cloudflare config apply logic
- chatHub broadcasts room danmaku over SSE; new subscribers replay the
last N messages on join so they don't face an empty room.
- Add a host-only external push endpoint POST /api/room/{room}/broadcast
(requires room:publish, Bearer token) that marks messages host:true.
- Slide-window rate limiter (room+sender+IP, 5 per 3s) guards both the
public chat and the broadcast endpoint.
- Wire RBAC room:chat policy, SPA routing and the room-creation route.
noelorin