Checkpoint: v4.0 media service, compose deploy, and verified docs

client/src/pages/Login.tsx

@@ -42,13 +42,14 @@ export default function Login() {
 
         <Card className="border-0 shadow-xl">
           <CardHeader className="text-center pb-2">
-            <CardTitle className="text-xl">开始训练</CardTitle>
+            <CardTitle className="text-xl" data-testid="login-title">开始训练</CardTitle>
             <CardDescription>输入用户名即可开始使用</CardDescription>
           </CardHeader>
           <CardContent>
             <form onSubmit={handleLogin} className="space-y-4">
               <div className="space-y-2">
                 <Input
+                  data-testid="login-username-input"
                   type="text"
                   placeholder="请输入您的用户名"
                   value={username}
@@ -59,6 +60,7 @@ export default function Login() {
                 />
               </div>
               <Button
+                data-testid="login-submit-button"
                 type="submit"
                 className="w-full h-12 text-base font-medium"
                 disabled={loginMutation.isPending || !username.trim()}