feat: 增加Oauth Claude账户usage接口缓存

src/routes/admin.js

@@ -2107,6 +2107,8 @@ router.get('/claude-accounts', authenticateAdmin, async (req, res) => {
 router.get('/claude-accounts/usage', authenticateAdmin, async (req, res) => {
   try {
     const accounts = await redis.getAllClaudeAccounts()
+    const now = Date.now()
+    const usageCacheTtlMs = 300 * 1000
 
     // 批量并发获取所有活跃 OAuth 账户的 Usage
     const usagePromises = accounts.map(async (account) => {
@@ -2121,6 +2123,19 @@ router.get('/claude-accounts/usage', authenticateAdmin, async (req, res) => {
         account.accessToken &&
         account.status === 'active'
       ) {
+        // 若快照在 300 秒内更新，直接使用缓存避免频繁请求
+        const cachedUsage = claudeAccountService.buildClaudeUsageSnapshot(account)
+        const lastUpdatedAt = account.claudeUsageUpdatedAt
+          ? new Date(account.claudeUsageUpdatedAt).getTime()
+          : 0
+        const isCacheFresh = cachedUsage && lastUpdatedAt && now - lastUpdatedAt < usageCacheTtlMs
+        if (isCacheFresh) {
+          return {
+            accountId: account.id,
+            claudeUsage: cachedUsage
+          }
+        }
+
         try {
           const usageData = await claudeAccountService.fetchOAuthUsage(account.id)
           if (usageData) {