Refactor build and start scripts in package.json; add plugin to exclude debug files from production build in vite.config.ts; remove ConnectScreen component and replace with ConnectionPlaceholder in multiple pages; update DeviceContext to auto-connect using device IP from URL; enhance locale files with new device IP labels.

client/src/pages/AIPage.tsx

@@ -7,7 +7,7 @@
    Backend: /sse/question (SSE), /sse/messages, /sse/chats, /sse/clear
    ============================================================ */
 import BottomNav from "@/components/BottomNav";
-import ConnectScreen from "@/components/ConnectScreen";
+import ConnectionPlaceholder from "@/components/ConnectionPlaceholder";
 import { useDevice } from "@/contexts/DeviceContext";
 import {
   AI_SPLIT_RESTORE_PATH_KEY,
@@ -337,7 +337,7 @@ export default function AIPage({ variant = "page", onClose }: AIPageProps = {})
     })();
   }, [mac, loadChat]);
 
-  // 没有 mac 时（设备未识别完毕）不应该停在 initializing；ConnectScreen 会拦截
+  // 没有 mac 时（设备未识别完毕）不应该停在 initializing；未连接时 ConnectionPlaceholder 会拦截
   useEffect(() => {
     if (!mac && initializing) {
       // 给 mac 一段缓冲期，否则即便最终没有 mac 也要释放欢迎页
@@ -692,7 +692,7 @@ export default function AIPage({ variant = "page", onClose }: AIPageProps = {})
 
   const headerTitle = aiText.title;
 
-  if (!isConnected) return <ConnectScreen />;
+  if (!isConnected) return <ConnectionPlaceholder />;
 
   return (
     <div