feat(crypto-tail): 尾盘策略页币安 API 状态监控与重连间隔调整

- 尾盘策略页：进入时检测币安 API/WebSocket，异常时红色强提醒
- 异常时提供「重新检测」按钮，不跳转 API 健康页、不做 60s 轮询
- 文案面向小白：无法连接币安 API、需行情数据、稍后重新检测
- 多语言：zh-CN/zh-TW/en 新增 cryptoTailStrategy.binanceApiAlert
- 币安 K 线 WS 重连延迟由 10s 改为 3s

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/src/main/kotlin/com/wrbug/polymarketbot/service/binance/BinanceKlineService.kt

@@ -130,7 +130,7 @@ class BinanceKlineService {
     private fun scheduleReconnect() {
         if (reconnectJob?.isActive == true) return
         reconnectJob = scope.launch {
-            delay(10_000)
+            delay(3_000)
             reconnectJob = null
             ws5m?.close(1000, "reconnect")
             ws15m?.close(1000, "reconnect")

frontend/src/locales/en/common.json

@@ -1402,6 +1402,11 @@
     "rerunFailed": "Re-run failed"
   },
   "cryptoTailStrategy": {
+    "binanceApiAlert": {
+      "title": "Cannot connect to Binance API — strategy cannot run for now",
+      "description": "Tail strategy needs Binance market data to work. The connection failed; this may be a network issue or Binance outage. Try again later by clicking the button below.",
+      "recheck": "Re-check"
+    },
     "list": {
       "title": "Crypto Tail Strategy",
       "walletTip": "Use a dedicated wallet for tail strategy. Do not use it for manual trading or copy trading to avoid balance/position issues.",

frontend/src/locales/zh-CN/common.json

@@ -1401,6 +1401,11 @@
     "rerunFailed": "重新测试失败"
   },
   "cryptoTailStrategy": {
+    "binanceApiAlert": {
+      "title": "无法连接币安 API，策略暂时不能运行",
+      "description": "尾盘策略需要从币安获取行情数据才能工作。当前连接失败，可能是网络问题或币安服务异常，请稍后点击下方按钮重新检测。",
+      "recheck": "重新检测"
+    },
     "list": {
       "title": "加密尾盘策略",
       "walletTip": "请使用单独的钱包运行尾盘策略，避免该钱包用于手动交易、跟单等其他操作，否则可能导致余额或仓位变化，造成策略执行异常。",

frontend/src/locales/zh-TW/common.json

@@ -1402,6 +1402,11 @@
     "rerunFailed": "重新測試失敗"
   },
   "cryptoTailStrategy": {
+    "binanceApiAlert": {
+      "title": "無法連接幣安 API，策略暫時不能運行",
+      "description": "尾盤策略需要從幣安取得行情資料才能運作。目前連線失敗，可能是網路問題或幣安服務異常，請稍後點擊下方按鈕重新檢測。",
+      "recheck": "重新檢測"
+    },
     "list": {
       "title": "加密尾盤策略",
       "walletTip": "請使用單獨的錢包運行尾盤策略，避免該錢包用於手動交易、跟單等其他操作，否則可能導致餘額或倉位變化，造成策略執行異常。",

frontend/src/pages/CryptoTailStrategyList.tsx

@@ -19,7 +19,7 @@ import {
   Spin,
   Tooltip
 } from 'antd'
-import { PlusOutlined, EditOutlined, UnorderedListOutlined, InfoCircleOutlined } from '@ant-design/icons'
+import { PlusOutlined, EditOutlined, UnorderedListOutlined, InfoCircleOutlined, WarningOutlined } from '@ant-design/icons'
 import { useTranslation } from 'react-i18next'
 import { useMediaQuery } from 'react-responsive'
 import { apiService } from '../services/api'
@@ -47,12 +47,41 @@ const CryptoTailStrategyList: React.FC = () => {
   const [triggersLoading, setTriggersLoading] = useState(false)
   const [form] = Form.useForm()
 
+  /** 币安 API 健康状态：仅保留「不可用」的项，用于强提醒 */
+  const [binanceUnhealthy, setBinanceUnhealthy] = useState<Array<{ name: string; message: string }>>([])
+  const [binanceCheckLoading, setBinanceCheckLoading] = useState(false)
+
+  const BINANCE_API_NAMES = ['币安 API', '币安 WebSocket']
+
+  const fetchBinanceApiStatus = async () => {
+    setBinanceCheckLoading(true)
+    try {
+      const res = await apiService.proxyConfig.checkApiHealth()
+      if (res.data.code === 0 && res.data.data?.apis) {
+        const unhealthy = res.data.data.apis.filter(
+          (api) => BINANCE_API_NAMES.includes(api.name) && api.status !== 'success'
+        )
+        setBinanceUnhealthy(unhealthy.map((api) => ({ name: api.name, message: api.message })))
+      } else {
+        setBinanceUnhealthy([])
+      }
+    } catch {
+      setBinanceUnhealthy([{ name: '币安 API', message: '' }, { name: '币安 WebSocket', message: '' }])
+    } finally {
+      setBinanceCheckLoading(false)
+    }
+  }
+
   useEffect(() => {
     fetchAccounts()
     fetchSystemConfig()
     fetchMarketOptions()
   }, [])
 
+  useEffect(() => {
+    fetchBinanceApiStatus()
+  }, [])
+
   useEffect(() => {
     fetchList()
   }, [filters])
@@ -411,6 +440,37 @@ const CryptoTailStrategyList: React.FC = () => {
   return (
     <div style={{ padding: isMobile ? 12 : 24 }}>
       <h1 style={{ marginBottom: 16, fontSize: isMobile ? 20 : 24 }}>{t('cryptoTailStrategy.list.title')}</h1>
+      {binanceUnhealthy.length > 0 && (
+        <Alert
+          type="error"
+          showIcon
+          icon={<WarningOutlined />}
+          message={t('cryptoTailStrategy.binanceApiAlert.title')}
+          description={
+            <div>
+              <p style={{ marginBottom: 8 }}>{t('cryptoTailStrategy.binanceApiAlert.description')}</p>
+              <ul style={{ marginBottom: 8, paddingLeft: 20 }}>
+                {binanceUnhealthy.map((item, i) => (
+                  <li key={i}>
+                    <strong>{item.name}</strong>
+                    {item.message ? `: ${item.message}` : ''}
+                  </li>
+                ))}
+              </ul>
+              <Button
+                type="primary"
+                danger
+                size="small"
+                loading={binanceCheckLoading}
+                onClick={fetchBinanceApiStatus}
+              >
+                {t('cryptoTailStrategy.binanceApiAlert.recheck')}
+              </Button>
+            </div>
+          }
+          style={{ marginBottom: 16 }}
+        />
+      )}
       <Alert
         type="warning"
         showIcon