feat: add quota limit for API key accounts

- Add configurable spending limit (quota_limit) for apikey-type accounts
- Atomic quota accumulation via PostgreSQL JSONB operations on TotalCost
- Scheduler filters out over-quota accounts with outbox-triggered snapshot refresh
- Display quota usage ($used / $limit) in account capacity column
- Add "Reset Quota" action in account menu to reset usage to zero
- Editing account settings preserves quota_used (no accidental reset)
- Covers all 3 billing paths: Anthropic, Gemini, OpenAI RecordUsage

chore: bump version to 0.1.90.4

frontend/src/components/account/AccountCapacityCell.vue

@@ -71,6 +71,24 @@
         <span class="text-[9px] opacity-60">{{ rpmStrategyTag }}</span>
       </span>
     </div>
+
+    <!-- API Key 账号配额限制 -->
+    <div v-if="showQuotaLimit" class="flex items-center gap-1">
+      <span
+        :class="[
+          'inline-flex items-center gap-1 rounded-md px-1.5 py-0.5 text-[10px] font-medium',
+          quotaClass
+        ]"
+        :title="quotaTooltip"
+      >
+        <svg class="h-2.5 w-2.5" fill="none" viewBox="0 0 24 24" stroke="currentColor" stroke-width="2">
+          <path stroke-linecap="round" stroke-linejoin="round" d="M2.25 18.75a60.07 60.07 0 0115.797 2.101c.727.198 1.453-.342 1.453-1.096V18.75M3.75 4.5v.75A.75.75 0 013 6h-.75m0 0v-.375c0-.621.504-1.125 1.125-1.125H20.25M2.25 6v9m18-10.5v.75c0 .414.336.75.75.75h.75m-1.5-1.5h.375c.621 0 1.125.504 1.125 1.125v9.75c0 .621-.504 1.125-1.125 1.125h-.375m1.5-1.5H21a.75.75 0 00-.75.75v.75m0 0H3.75m0 0h-.375a1.125 1.125 0 01-1.125-1.125V15m1.5 1.5v-.75A.75.75 0 003 15h-.75M15 10.5a3 3 0 11-6 0 3 3 0 016 0zm3 0h.008v.008H18V10.5zm-12 0h.008v.008H6V10.5z" />
+        </svg>
+        <span class="font-mono">${{ formatCost(currentQuotaUsed) }}</span>
+        <span class="text-gray-400 dark:text-gray-500">/</span>
+        <span class="font-mono">${{ formatCost(account.quota_limit) }}</span>
+      </span>
+    </div>
   </div>
 </template>
 
@@ -286,6 +304,48 @@ const rpmTooltip = computed(() => {
   }
 })
 
+// 是否显示配额限制（仅 apikey 类型且设置了 quota_limit）
+const showQuotaLimit = computed(() => {
+  return (
+    props.account.type === 'apikey' &&
+    props.account.quota_limit !== undefined &&
+    props.account.quota_limit !== null &&
+    props.account.quota_limit > 0
+  )
+})
+
+// 当前已用配额
+const currentQuotaUsed = computed(() => props.account.quota_used ?? 0)
+
+// 配额状态样式
+const quotaClass = computed(() => {
+  if (!showQuotaLimit.value) return ''
+
+  const used = currentQuotaUsed.value
+  const limit = props.account.quota_limit || 0
+
+  if (used >= limit) {
+    return 'bg-red-100 text-red-700 dark:bg-red-900/30 dark:text-red-400'
+  }
+  if (used >= limit * 0.8) {
+    return 'bg-yellow-100 text-yellow-700 dark:bg-yellow-900/30 dark:text-yellow-400'
+  }
+  return 'bg-emerald-100 text-emerald-700 dark:bg-emerald-900/30 dark:text-emerald-400'
+})
+
+// 配额提示文字
+const quotaTooltip = computed(() => {
+  if (!showQuotaLimit.value) return ''
+
+  const used = currentQuotaUsed.value
+  const limit = props.account.quota_limit || 0
+
+  if (used >= limit) {
+    return t('admin.accounts.capacity.quota.exceeded')
+  }
+  return t('admin.accounts.capacity.quota.normal')
+})
+
 // 格式化费用显示
 const formatCost = (value: number | null | undefined) => {
   if (value === null || value === undefined) return '0'