feat(antigravity): 从 LoadCodeAssist 复用 TierInfo 提取 plan_type

复用已有 GetTier() 返回的 tier ID（free-tier / g1-pro-tier /
g1-ultra-tier），通过 TierIDToPlanType 映射为 Free / Pro / Ultra，
在 loadProjectIDWithRetry 中顺带提取并写入 credentials.plan_type；
前端增加 Abnormal 异常套餐红色标记。

Made-with: Cursor

frontend/src/components/common/PlatformTypeBadge.vue

@@ -31,7 +31,7 @@
     </div>
     <!-- Row 2: Plan type + Privacy mode (only if either exists) -->
     <div v-if="planLabel || privacyBadge" class="inline-flex items-center overflow-hidden rounded-md">
-      <span v-if="planLabel" :class="['inline-flex items-center gap-1 px-1.5 py-1', typeClass]">
+      <span v-if="planLabel" :class="['inline-flex items-center gap-1 px-1.5 py-1', planBadgeClass]">
         <span>{{ planLabel }}</span>
       </span>
       <span
@@ -102,6 +102,8 @@ const planLabel = computed(() => {
       return 'Pro'
     case 'free':
       return 'Free'
+    case 'abnormal':
+      return t('admin.accounts.subscriptionAbnormal')
     default:
       return props.planType
   }
@@ -139,6 +141,13 @@ const typeClass = computed(() => {
   return 'bg-blue-100 text-blue-600 dark:bg-blue-900/30 dark:text-blue-400'
 })
 
+const planBadgeClass = computed(() => {
+  if (props.planType && props.planType.toLowerCase() === 'abnormal') {
+    return 'bg-red-100 text-red-600 dark:bg-red-900/30 dark:text-red-400'
+  }
+  return typeClass.value
+})
+
 // Privacy badge — shows different states for OpenAI/Antigravity OAuth privacy setting
 const privacyBadge = computed(() => {
   if (props.type !== 'oauth' || !props.privacyMode) return null