fix: prevent duplicate login requests

- Add isSubmitting guard to prevent multiple concurrent login requests
- Set loading and submitting flags before validation to avoid race conditions
- This fixes the issue where multiple /login requests were fired simultaneously

ruoyi-ui-next/src/views/login.vue

@@ -51,6 +51,7 @@ const router = useRouter()
 const userStore = useUserStore()
 const formRef = ref<FormInstance>()
 const loading = ref(false)
+const isSubmitting = ref(false)
 
 const loginForm = reactive({
   username: '',
@@ -63,12 +64,13 @@ const rules = {
 }
 
 const handleLogin = async () => {
-  if (!formRef.value) return
+  if (!formRef.value || isSubmitting.value) return
 
+  isSubmitting.value = true
+  loading.value = true
   try {
     // 使用 Promise 方式等待校验完成
     await formRef.value.validate()
-    loading.value = true
     await userStore.login(loginForm.username, loginForm.password)
     ElMessage.success('登录成功')
     // 使用 window.location.replace 确保页面完全刷新并跳转到首页
@@ -78,6 +80,7 @@ const handleLogin = async () => {
     ElMessage.error(error.message || '登录失败，请检查用户名和密码')
   } finally {
     loading.value = false
+    isSubmitting.value = false
   }
 }
 </script>