Add AI playground and frontend layout guidelines

planet.sh

@@ -1236,8 +1236,8 @@ start() {
     log_success "启动完成"
     log_note "智能星球计划: http://localhost:${FRONTEND_PORT}/earth"
     log_note "智能星球仪表盘: http://localhost:${FRONTEND_PORT}/admin"
+    log_note "AI Playground: http://localhost:${FRONTEND_PORT}/playground"
     log_note "智能星球开发文档: http://localhost:${BACKEND_PORT}/docs"
-    log_note "智能星球AI: http://localhost:${AI_PROVIDER_PORT}/chat"
 }
 
 stop() {