fix(frontend): 完善表单校验并添加错误提示

- UserEditModal: 添加 email 必填和 concurrency 最小值校验
- UserAttributesConfigModal: 添加 key/name 必填和 options 非空校验
- GroupsView: 添加 name 必填校验
- ProxiesView: 添加 name/host 必填和 port 范围校验
- UserBalanceModal: 添加 amount 有效性和余额充足性校验
- RedeemView: 添加空兑换码错误提示
- i18n: 添加所有新增校验的中英文翻译

frontend/src/components/admin/user/UserEditModal.vue

@@ -86,6 +86,14 @@ const copyPassword = async () => {
 }
 const handleUpdateUser = async () => {
   if (!props.user) return
+  if (!form.email.trim()) {
+    appStore.showError(t('admin.users.emailRequired'))
+    return
+  }
+  if (form.concurrency < 1) {
+    appStore.showError(t('admin.users.concurrencyMin'))
+    return
+  }
   submitting.value = true
   try {
     const data: any = { email: form.email, username: form.username, notes: form.notes, concurrency: form.concurrency }