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>

scripts/generate-env.mjs

@@ -639,6 +639,7 @@ const APP_CONFIGS = [
 		path: 'services/llm-playground/.env',
 		vars: {
 			PUBLIC_MANA_LLM_URL: (env) => env.MANA_LLM_URL || 'http://localhost:3025',
+			PUBLIC_MANA_CORE_AUTH_URL: (env) => env.MANA_CORE_AUTH_URL || 'http://localhost:3001',
 		},
 	},