feat: add beta environment banner

Add beta environment warning banner for Cloud beta deployments with i18n support (zh/en/ja)

web/src/app/RootLayout.tsx

@@ -1,9 +1,15 @@
 import { Outlet } from 'react-router-dom';
 import { useDocumentTitle } from '@/hooks/useDocumentTitle';
+import { BetaBanner } from '@/components/BetaBanner';
 
 // Top-level route layout: drives the dynamic document title from the active
 // route and renders the matched child route via <Outlet />.
 export default function RootLayout() {
   useDocumentTitle();
-  return <Outlet />;
+  return (
+    <>
+      <BetaBanner />
+      <Outlet />
+    </>
+  );
 }

web/src/app/infra/entities/api/index.ts

@@ -566,6 +566,8 @@ export interface ApiRespSystemInfo {
   debug: boolean;
   version: string;
   edition: string;
+  beta: boolean;
+  deployment_mode: 'cloud' | 'oss';
   /** Independent instance-level gate for local stdio MCP transports. */
   mcp_stdio_enabled: boolean;
   cloud_service_url: string;

web/src/app/infra/http/index.ts

@@ -25,6 +25,8 @@ export const systemInfo: ApiRespSystemInfo = {
   debug: false,
   version: '',
   edition: 'community',
+  beta: false,
+  deployment_mode: 'oss',
   mcp_stdio_enabled: false,
   enable_marketplace: true,
   cloud_service_url: '',