fix(frontend): login P0 — 去卡头重复、offline 文案、显密可键盘

去掉卡内盾牌标题；后端不可用改为「服务暂不可用」并禁用登录钮；显密切换可 Tab 聚焦。

frontend/src/i18n/locales/en/common.ts

@@ -11,6 +11,7 @@ export default {
     collectors: 'Log Collectors',
     logs: 'Log Query',
     alerts: 'Alerts',
+    analysis: 'Log Analysis',
     settings: 'Settings',
     users: 'Users',
     login: 'Sign In',
@@ -42,8 +43,10 @@ export default {
     errCredential: 'Invalid username or password',
     errConn: 'Cannot reach the backend. Make sure it is running on port 8080.',
     errFallback: 'Sign-in failed',
-    backendDown: 'Backend is not running',
-    backendDownHint: 'Cannot reach the API service. Start the backend first:',
+    backendDown: 'Service temporarily unavailable',
+    showPassword: 'Show password',
+    hidePassword: 'Hide password',
+    backendDownHint: 'Cannot reach the service. Try again later or contact an admin.',
   },
   dialog: {
     confirmTitle: 'Confirm Deletion',
@@ -92,6 +95,17 @@ export default {
   spinner: {
     default: 'Loading...',
   },
+  range: {
+    lastMinutes: 'Last {{count}} minutes',
+    lastHours: 'Last {{count}} hours',
+    lastHours_one: 'Last {{count}} hour',
+    custom: 'Custom time',
+    title: 'Select time range',
+    start: 'Start time',
+    end: 'End time',
+    apply: 'Apply',
+    recent: 'Recently used',
+  },
   password: {
     hide: 'Hide password',
     show: 'Show password',

frontend/src/i18n/locales/zh/common.ts

@@ -11,6 +11,7 @@ export default {
     collectors: '日志采集',
     logs: '日志查询',
     alerts: '日志告警',
+    analysis: '日志分析',
     settings: '系统设置',
     users: '用户管理',
     login: '登录',
@@ -42,8 +43,10 @@ export default {
     errCredential: '用户名或密码错误',
     errConn: '无法连接后端服务，请确认后端已启动（端口 8080）。',
     errFallback: '登录失败',
-    backendDown: '后端服务未启动',
-    backendDownHint: '无法连接 API 服务，请先启动后端：',
+    backendDown: '服务暂不可用',
+    showPassword: '显示密码',
+    hidePassword: '隐藏密码',
+    backendDownHint: '暂时连不上服务，请稍后再试或联系管理员。',
   },
   dialog: {
     confirmTitle: '确认删除',
@@ -92,6 +95,16 @@ export default {
   spinner: {
     default: '加载中...',
   },
+  range: {
+    lastMinutes: '最近 {{count}} 分钟',
+    lastHours: '最近 {{count}} 小时',
+    custom: '自定义时间',
+    title: '选择时间范围',
+    start: '开始时间',
+    end: '结束时间',
+    apply: '应用时间',
+    recent: '最近使用',
+  },
   password: {
     hide: '隐藏密码',
     show: '显示密码',

frontend/src/pages/login/index.tsx

@@ -1,7 +1,7 @@
 import { memo, useCallback, useEffect, useState } from 'react'
 import { useTranslation } from 'react-i18next'
 import { useLocation, useNavigate } from 'react-router'
-import { Activity, Eye, EyeOff, Shield, ServerOff } from 'lucide-react'
+import { Activity, Eye, EyeOff, ServerOff } from 'lucide-react'
 import { Button } from '@/components/ui/button'
 import { Checkbox } from '@/components/ui/checkbox'
 import { Input } from '@/components/ui/input'
@@ -106,20 +106,12 @@ const Login = memo(function Login() {
             <div>
               <p className="text-sm font-medium text-warning">{t('login.backendDown')}</p>
               <p className="text-xs text-warning mt-1">{t('login.backendDownHint')}</p>
-              <code className="block mt-2 px-3 py-2 bg-warning/20 rounded text-xs font-mono text-warning">
-                ./run.sh
-              </code>
             </div>
           </div>
         )}
 
         {/* Login Card */}
         <div className="bg-card rounded-2xl shadow-lg border border-border p-8">
-          <div className="flex items-center gap-2 mb-6">
-            <Shield className="w-5 h-5 text-primary" />
-            <h2 className="text-lg font-semibold text-foreground">{t('login.heading')}</h2>
-          </div>
-
           {error && (
             <div className="mb-4 p-3 rounded-lg bg-destructive/10 border border-destructive/30 text-destructive text-sm">
               {error}
@@ -157,7 +149,7 @@ const Login = memo(function Login() {
                   type="button"
                   onClick={togglePassword}
                   className="absolute right-3 top-1/2 -translate-y-1/2 text-muted-foreground hover:text-foreground"
-                  tabIndex={-1}
+                  aria-label={showPassword ? t('login.hidePassword') : t('login.showPassword')}
                 >
                   {showPassword ? (
                     <EyeOff className="w-4 h-4" />
@@ -182,7 +174,7 @@ const Login = memo(function Login() {
             <Button
               type="submit"
               className="w-full h-10 bg-primary hover:bg-primary/90 text-primary-foreground"
-              disabled={loading}
+              disabled={loading || backendStatus === 'offline'}
             >
               {loading ? t('login.submitting') : t('login.submit')}
             </Button>