feat(llm-playground): add production deployment with auth

- Add Dockerfile for multi-stage Docker build
- Add mana-core-auth integration with login/register pages
- Add auth store using Svelte 5 runes
- Add protected route layout with auth guard
- Add health endpoint for container health checks
- Add runtime URL injection via hooks.server.ts
- Add logout button to header
- Update docker-compose.macmini.yml with llm-playground service
- Update cloudflared-config.yml with playground.mana.how route
- Update mana-llm CORS config for playground domain
- Update generate-env.mjs with auth URL variable

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cloudflared-config.yml

@@ -36,6 +36,12 @@ ingress:
   - hostname: nutriphi-api.mana.how
     service: http://localhost:3023
 
+  # LLM Services
+  - hostname: playground.mana.how
+    service: http://localhost:5190
+  - hostname: llm.mana.how
+    service: http://localhost:3025
+
   # Monitoring & Tools
   - hostname: grafana.mana.how
     service: http://localhost:3100