refactor(antigravity): 统一额度刷新机制与 Claude 一致

将 Antigravity 的额度刷新从后台定时刷新改为按需获取模式，与 Claude 统一：

- 删除 AntigravityQuotaRefresher 后台服务
- 新增 QuotaFetcher 接口和 AntigravityQuotaFetcher 实现
- 前端改为调用 usage API 获取额度，支持 loading/error 状态
- 统一使用内存缓存（10 分钟 TTL）

frontend/src/components/account/AccountUsageCell.vue

@@ -93,7 +93,7 @@
       <div v-else class="text-xs text-gray-400">-</div>
     </template>
 
-    <!-- Antigravity OAuth accounts: show quota from extra field -->
+    <!-- Antigravity OAuth accounts: fetch usage from API -->
     <template v-else-if="account.platform === 'antigravity' && account.type === 'oauth'">
       <!-- 账户类型徽章 -->
       <div v-if="antigravityTierLabel" class="mb-1 flex items-center gap-1">
@@ -129,40 +129,55 @@
         </span>
       </div>
 
-      <div v-if="hasAntigravityQuota" class="space-y-1">
+      <!-- Loading state -->
+      <div v-if="loading" class="space-y-1.5">
+        <div class="flex items-center gap-1">
+          <div class="h-3 w-[32px] animate-pulse rounded bg-gray-200 dark:bg-gray-700"></div>
+          <div class="h-1.5 w-8 animate-pulse rounded-full bg-gray-200 dark:bg-gray-700"></div>
+          <div class="h-3 w-[32px] animate-pulse rounded bg-gray-200 dark:bg-gray-700"></div>
+        </div>
+      </div>
+
+      <!-- Error state -->
+      <div v-else-if="error" class="text-xs text-red-500">
+        {{ error }}
+      </div>
+
+      <!-- Usage data from API -->
+      <div v-else-if="hasAntigravityQuotaFromAPI" class="space-y-1">
         <!-- Gemini 3 Pro -->
         <UsageProgressBar
-          v-if="antigravity3ProUsage !== null"
+          v-if="antigravity3ProUsageFromAPI !== null"
           :label="t('admin.accounts.usageWindow.gemini3Pro')"
-          :utilization="antigravity3ProUsage.utilization"
-          :resets-at="antigravity3ProUsage.resetTime"
+          :utilization="antigravity3ProUsageFromAPI.utilization"
+          :resets-at="antigravity3ProUsageFromAPI.resetTime"
           color="indigo"
         />
 
         <!-- Gemini 3 Flash -->
         <UsageProgressBar
-          v-if="antigravity3FlashUsage !== null"
+          v-if="antigravity3FlashUsageFromAPI !== null"
           :label="t('admin.accounts.usageWindow.gemini3Flash')"
-          :utilization="antigravity3FlashUsage.utilization"
-          :resets-at="antigravity3FlashUsage.resetTime"
+          :utilization="antigravity3FlashUsageFromAPI.utilization"
+          :resets-at="antigravity3FlashUsageFromAPI.resetTime"
           color="emerald"
         />
 
         <!-- Gemini 3 Image -->
         <UsageProgressBar
-          v-if="antigravity3ImageUsage !== null"
+          v-if="antigravity3ImageUsageFromAPI !== null"
           :label="t('admin.accounts.usageWindow.gemini3Image')"
-          :utilization="antigravity3ImageUsage.utilization"
-          :resets-at="antigravity3ImageUsage.resetTime"
+          :utilization="antigravity3ImageUsageFromAPI.utilization"
+          :resets-at="antigravity3ImageUsageFromAPI.resetTime"
           color="purple"
         />
 
         <!-- Claude 4.5 -->
         <UsageProgressBar
-          v-if="antigravityClaude45Usage !== null"
+          v-if="antigravityClaude45UsageFromAPI !== null"
           :label="t('admin.accounts.usageWindow.claude45')"
-          :utilization="antigravityClaude45Usage.utilization"
-          :resets-at="antigravityClaude45Usage.resetTime"
+          :utilization="antigravityClaude45UsageFromAPI.utilization"
+          :resets-at="antigravityClaude45UsageFromAPI.resetTime"
           color="amber"
         />
       </div>
@@ -295,6 +310,9 @@ const shouldFetchUsage = computed(() => {
   if (props.account.platform === 'gemini') {
     return props.account.type === 'oauth'
   }
+  if (props.account.platform === 'antigravity') {
+    return props.account.type === 'oauth'
+  }
   return false
 })
 
@@ -453,45 +471,35 @@ const codex7dResetAt = computed(() => {
   return null
 })
 
-// Antigravity quota types
-interface AntigravityModelQuota {
-  remaining: number // 剩余百分比 0-100
-  reset_time: string // ISO 8601 重置时间
-}
-
-interface AntigravityQuotaData {
-  [model: string]: AntigravityModelQuota
-}
-
+// Antigravity quota types (用于 API 返回的数据)
 interface AntigravityUsageResult {
   utilization: number
   resetTime: string | null
 }
 
-// Antigravity quota computed properties
-const hasAntigravityQuota = computed(() => {
-  const extra = props.account.extra as Record<string, unknown> | undefined
-  return extra && typeof extra.quota === 'object' && extra.quota !== null
+// ===== Antigravity quota from API (usageInfo.antigravity_quota) =====
+
+// 检查是否有从 API 获取的配额数据
+const hasAntigravityQuotaFromAPI = computed(() => {
+  return usageInfo.value?.antigravity_quota && Object.keys(usageInfo.value.antigravity_quota).length > 0
 })
 
-// 从配额数据中获取使用率（多模型取最低剩余 = 最高使用）
-const getAntigravityUsage = (
+// 从 API 配额数据中获取使用率（多模型取最高使用率）
+const getAntigravityUsageFromAPI = (
   modelNames: string[]
 ): AntigravityUsageResult | null => {
-  const extra = props.account.extra as Record<string, unknown> | undefined
-  if (!extra || typeof extra.quota !== 'object' || extra.quota === null) return null
+  const quota = usageInfo.value?.antigravity_quota
+  if (!quota) return null
 
-  const quota = extra.quota as AntigravityQuotaData
-
-  let minRemaining = 100
+  let maxUtilization = 0
   let earliestReset: string | null = null
 
   for (const model of modelNames) {
     const modelQuota = quota[model]
     if (!modelQuota) continue
 
-    if (modelQuota.remaining < minRemaining) {
-      minRemaining = modelQuota.remaining
+    if (modelQuota.utilization > maxUtilization) {
+      maxUtilization = modelQuota.utilization
     }
     if (modelQuota.reset_time) {
       if (!earliestReset || modelQuota.reset_time < earliestReset) {
@@ -501,32 +509,31 @@ const getAntigravityUsage = (
   }
 
   // 如果没有找到任何匹配的模型
-  if (minRemaining === 100 && earliestReset === null) {
-    // 检查是否至少有一个模型有数据
+  if (maxUtilization === 0 && earliestReset === null) {
     const hasAnyData = modelNames.some((m) => quota[m])
     if (!hasAnyData) return null
   }
 
   return {
-    utilization: 100 - minRemaining,
+    utilization: maxUtilization,
     resetTime: earliestReset
   }
 }
 
-// Gemini 3 Pro: gemini-3-pro-low, gemini-3-pro-high, gemini-3-pro-preview
-const antigravity3ProUsage = computed(() =>
-  getAntigravityUsage(['gemini-3-pro-low', 'gemini-3-pro-high', 'gemini-3-pro-preview'])
+// Gemini 3 Pro from API
+const antigravity3ProUsageFromAPI = computed(() =>
+  getAntigravityUsageFromAPI(['gemini-3-pro-low', 'gemini-3-pro-high', 'gemini-3-pro-preview'])
 )
 
-// Gemini 3 Flash: gemini-3-flash
-const antigravity3FlashUsage = computed(() => getAntigravityUsage(['gemini-3-flash']))
+// Gemini 3 Flash from API
+const antigravity3FlashUsageFromAPI = computed(() => getAntigravityUsageFromAPI(['gemini-3-flash']))
 
-// Gemini 3 Image: gemini-3-pro-image
-const antigravity3ImageUsage = computed(() => getAntigravityUsage(['gemini-3-pro-image']))
+// Gemini 3 Image from API
+const antigravity3ImageUsageFromAPI = computed(() => getAntigravityUsageFromAPI(['gemini-3-pro-image']))
 
-// Claude 4.5: claude-sonnet-4-5, claude-opus-4-5-thinking
-const antigravityClaude45Usage = computed(() =>
-  getAntigravityUsage(['claude-sonnet-4-5', 'claude-opus-4-5-thinking'])
+// Claude 4.5 from API
+const antigravityClaude45UsageFromAPI = computed(() =>
+  getAntigravityUsageFromAPI(['claude-sonnet-4-5', 'claude-opus-4-5-thinking'])
 )
 
 // Antigravity 账户类型（从 load_code_assist 响应中提取）

frontend/src/types/index.ts

@@ -376,6 +376,12 @@ export interface UsageProgress {
   window_stats?: WindowStats | null // 窗口期统计（从窗口开始到当前的使用量）
 }
 
+// Antigravity 单个模型的配额信息
+export interface AntigravityModelQuota {
+  utilization: number // 使用率 0-100
+  reset_time: string  // 重置时间 ISO8601
+}
+
 export interface AccountUsageInfo {
   updated_at: string | null
   five_hour: UsageProgress | null
@@ -383,6 +389,7 @@ export interface AccountUsageInfo {
   seven_day_sonnet: UsageProgress | null
   gemini_pro_daily?: UsageProgress | null
   gemini_flash_daily?: UsageProgress | null
+  antigravity_quota?: Record<string, AntigravityModelQuota> | null
 }
 
 // OpenAI Codex usage snapshot (from response headers)