fix(antigravity): fetch default mapping from API and sync Redis on rate limit

1. Frontend: replace hardcoded antigravityDefaultMappings with async
   fetch from GET /admin/accounts/antigravity/default-model-mapping,
   eliminating the duplicate data source that caused frontend/backend
   mapping inconsistency.

2. Backend: convert handleSmartRetry and antigravityRetryLoop from
   standalone functions to AntigravityGatewayService methods, enabling
   Redis cache sync (updateAccountModelRateLimitInCache) after both
   rate-limit write paths — long-delay branch and retry-exhausted branch.

backend/internal/service/antigravity_gateway_service.go

@@ -136,7 +136,7 @@ type smartRetryResult struct {
 
 // handleSmartRetry 处理 OAuth 账号的智能重试逻辑
 // 将 429/503 限流处理逻辑抽取为独立函数，减少 antigravityRetryLoop 的复杂度
-func handleSmartRetry(p antigravityRetryLoopParams, resp *http.Response, respBody []byte, baseURL string, urlIdx int, availableURLs []string) *smartRetryResult {
+func (s *AntigravityGatewayService) handleSmartRetry(p antigravityRetryLoopParams, resp *http.Response, respBody []byte, baseURL string, urlIdx int, availableURLs []string) *smartRetryResult {
 	// "Resource has been exhausted" 是 URL 级别限流，切换 URL（仅 429）
 	if resp.StatusCode == http.StatusTooManyRequests && isURLLevelRateLimit(respBody) && urlIdx < len(availableURLs)-1 {
 		log.Printf("%s URL fallback (429): %s -> %s", p.prefix, baseURL, availableURLs[urlIdx+1])
@@ -155,6 +155,8 @@ func handleSmartRetry(p antigravityRetryLoopParams, resp *http.Response, respBod
 		if !setModelRateLimitByModelName(p.ctx, p.accountRepo, p.account.ID, modelName, p.prefix, resp.StatusCode, resetAt, false) {
 			p.handleError(p.ctx, p.prefix, p.account, resp.StatusCode, resp.Header, respBody, p.quotaScope, p.groupID, p.sessionHash, p.isStickySession)
 			log.Printf("%s status=%d rate_limited account=%d (no scope mapping)", p.prefix, resp.StatusCode, p.account.ID)
+		} else {
+			s.updateAccountModelRateLimitInCache(p.ctx, p.account, modelName, resetAt)
 		}
 
 		// 返回账号切换信号，让上层切换账号重试
@@ -241,6 +243,7 @@ func handleSmartRetry(p antigravityRetryLoopParams, resp *http.Response, respBod
 			} else {
 				log.Printf("%s status=%d model_rate_limited_after_smart_retry model=%s account=%d reset_in=%v",
 					p.prefix, resp.StatusCode, modelName, p.account.ID, antigravityDefaultRateLimitDuration)
+				s.updateAccountModelRateLimitInCache(p.ctx, p.account, modelName, resetAt)
 			}
 		}
 
@@ -260,7 +263,7 @@ func handleSmartRetry(p antigravityRetryLoopParams, resp *http.Response, respBod
 }
 
 // antigravityRetryLoop 执行带 URL fallback 的重试循环
-func antigravityRetryLoop(p antigravityRetryLoopParams) (*antigravityRetryLoopResult, error) {
+func (s *AntigravityGatewayService) antigravityRetryLoop(p antigravityRetryLoopParams) (*antigravityRetryLoopResult, error) {
 	// 预检查：如果账号已限流，根据剩余时间决定等待或切换
 	if p.requestedModel != "" {
 		if remaining := p.account.GetRateLimitRemainingTimeWithContext(p.ctx, p.requestedModel); remaining > 0 {
@@ -363,7 +366,7 @@ urlFallbackLoop:
 				_ = resp.Body.Close()
 
 				// 尝试智能重试处理（OAuth 账号专用）
-				smartResult := handleSmartRetry(p, resp, respBody, baseURL, urlIdx, availableURLs)
+				smartResult := s.handleSmartRetry(p, resp, respBody, baseURL, urlIdx, availableURLs)
 				switch smartResult.action {
 				case smartRetryActionContinueURL:
 					continue urlFallbackLoop
@@ -1025,7 +1028,7 @@ func (s *AntigravityGatewayService) Forward(ctx context.Context, c *gin.Context,
 	}
 
 	// 执行带重试的请求
-	result, err := antigravityRetryLoop(antigravityRetryLoopParams{
+	result, err := s.antigravityRetryLoop(antigravityRetryLoopParams{
 		ctx:             ctx,
 		prefix:          prefix,
 		account:         account,
@@ -1106,7 +1109,7 @@ func (s *AntigravityGatewayService) Forward(ctx context.Context, c *gin.Context,
 				if txErr != nil {
 					continue
 				}
-				retryResult, retryErr := antigravityRetryLoop(antigravityRetryLoopParams{
+				retryResult, retryErr := s.antigravityRetryLoop(antigravityRetryLoopParams{
 					ctx:             ctx,
 					prefix:          prefix,
 					account:         account,
@@ -1670,7 +1673,7 @@ func (s *AntigravityGatewayService) ForwardGemini(ctx context.Context, c *gin.Co
 	}
 
 	// 执行带重试的请求
-	result, err := antigravityRetryLoop(antigravityRetryLoopParams{
+	result, err := s.antigravityRetryLoop(antigravityRetryLoopParams{
 		ctx:             ctx,
 		prefix:          prefix,
 		account:         account,

frontend/src/api/admin/accounts.ts

@@ -387,6 +387,17 @@ export async function importData(payload: {
   return data
 }
 
+/**
+ * Get Antigravity default model mapping from backend
+ * @returns Default model mapping (from -> to)
+ */
+export async function getAntigravityDefaultModelMapping(): Promise<Record<string, string>> {
+  const { data } = await apiClient.get<Record<string, string>>(
+    '/admin/accounts/antigravity/default-model-mapping'
+  )
+  return data
+}
+
 export const accountsAPI = {
   list,
   getById,
@@ -412,7 +423,8 @@ export const accountsAPI = {
   bulkUpdate,
   syncFromCrs,
   exportData,
-  importData
+  importData,
+  getAntigravityDefaultModelMapping
 }
 
 export default accountsAPI

frontend/src/components/account/CreateAccountModal.vue

@@ -1980,7 +1980,7 @@ import {
   getModelsByPlatform,
   commonErrorCodes,
   buildModelMappingObject,
-  antigravityDefaultMappings,
+  fetchAntigravityDefaultMappings,
   isValidWildcardPattern
 } from '@/composables/useModelWhitelist'
 import { useAuthStore } from '@/stores/auth'
@@ -2270,7 +2270,9 @@ watch(
       // Antigravity: 默认使用映射模式并填充默认映射
       if (form.platform === 'antigravity') {
         antigravityModelRestrictionMode.value = 'mapping'
-        antigravityModelMappings.value = [...antigravityDefaultMappings]
+        fetchAntigravityDefaultMappings().then(mappings => {
+          antigravityModelMappings.value = [...mappings]
+        })
         antigravityWhitelistModels.value = []
       } else {
         antigravityWhitelistModels.value = []
@@ -2318,7 +2320,9 @@ watch(
     // Antigravity: 默认使用映射模式并填充默认映射
     if (newPlatform === 'antigravity') {
       antigravityModelRestrictionMode.value = 'mapping'
-      antigravityModelMappings.value = [...antigravityDefaultMappings]
+      fetchAntigravityDefaultMappings().then(mappings => {
+        antigravityModelMappings.value = [...mappings]
+      })
       antigravityWhitelistModels.value = []
       accountCategory.value = 'oauth-based'
       antigravityAccountType.value = 'oauth'
@@ -2576,7 +2580,9 @@ const resetForm = () => {
 
   antigravityModelRestrictionMode.value = 'mapping'
   antigravityWhitelistModels.value = []
-  antigravityModelMappings.value = [...antigravityDefaultMappings]
+  fetchAntigravityDefaultMappings().then(mappings => {
+    antigravityModelMappings.value = [...mappings]
+  })
   customErrorCodesEnabled.value = false
   selectedErrorCodes.value = []
   customErrorCodeInput.value = null

frontend/src/composables/useModelWhitelist.ts

@@ -273,39 +273,25 @@ const antigravityPresetMappings = [
   { label: 'Opus 4.5', from: 'claude-opus-4-5-thinking', to: 'claude-opus-4-5-thinking', color: 'bg-pink-100 text-pink-700 hover:bg-pink-200 dark:bg-pink-900/30 dark:text-pink-400' }
 ]
 
-// Antigravity 默认映射（与迁移脚本 049 保持一致）
+// Antigravity 默认映射（从后端 API 获取，与 constants.go 保持一致）
-// 基于官方 API 返回的模型列表，只支持 Claude 4.5+ 和 Gemini 2.5+
+// 使用 fetchAntigravityDefaultMappings() 异步获取
-// 精确匹配，无通配符
+import { getAntigravityDefaultModelMapping } from '@/api/admin/accounts'
-export const antigravityDefaultMappings: { from: string; to: string }[] = [
+
-  // Claude 白名单
+let _antigravityDefaultMappingsCache: { from: string; to: string }[] | null = null
-  { from: 'claude-opus-4-6', to: 'claude-opus-4-6' },
+
-  { from: 'claude-opus-4-5-thinking', to: 'claude-opus-4-5-thinking' },
+export async function fetchAntigravityDefaultMappings(): Promise<{ from: string; to: string }[]> {
-  { from: 'claude-sonnet-4-5', to: 'claude-sonnet-4-5' },
+  if (_antigravityDefaultMappingsCache !== null) {
-  { from: 'claude-sonnet-4-5-thinking', to: 'claude-sonnet-4-5-thinking' },
+    return _antigravityDefaultMappingsCache
-  // Claude 详细版本 ID 映射
+  }
-  { from: 'claude-opus-4-5-20251101', to: 'claude-opus-4-5-thinking' },
+  try {
-  { from: 'claude-sonnet-4-5-20250929', to: 'claude-sonnet-4-5' },
+    const mapping = await getAntigravityDefaultModelMapping()
-  // Claude Haiku → Sonnet（无 Haiku 支持）
+    _antigravityDefaultMappingsCache = Object.entries(mapping).map(([from, to]) => ({ from, to }))
-  { from: 'claude-haiku-4-5', to: 'claude-sonnet-4-5' },
+  } catch (e) {
-  { from: 'claude-haiku-4-5-20251001', to: 'claude-sonnet-4-5' },
+    console.warn('[fetchAntigravityDefaultMappings] API failed, using empty fallback', e)
-  // Gemini 2.5 白名单
+    _antigravityDefaultMappingsCache = []
-  { from: 'gemini-2.5-flash', to: 'gemini-2.5-flash' },
+  }
-  { from: 'gemini-2.5-flash-lite', to: 'gemini-2.5-flash-lite' },
+  return _antigravityDefaultMappingsCache
-  { from: 'gemini-2.5-flash-thinking', to: 'gemini-2.5-flash-thinking' },
+}
-  { from: 'gemini-2.5-pro', to: 'gemini-2.5-pro' },
-  // Gemini 3 白名单
-  { from: 'gemini-3-flash', to: 'gemini-3-flash' },
-  { from: 'gemini-3-pro-high', to: 'gemini-3-pro-high' },
-  { from: 'gemini-3-pro-low', to: 'gemini-3-pro-low' },
-  { from: 'gemini-3-pro-image', to: 'gemini-3-pro-image' },
-  // Gemini 3 preview 映射
-  { from: 'gemini-3-flash-preview', to: 'gemini-3-flash' },
-  { from: 'gemini-3-pro-preview', to: 'gemini-3-pro-high' },
-  { from: 'gemini-3-pro-image-preview', to: 'gemini-3-pro-image' },
-  // 其他官方模型
-  { from: 'gpt-oss-120b-medium', to: 'gpt-oss-120b-medium' },
-  { from: 'tab_flash_lite_preview', to: 'tab_flash_lite_preview' }
-]
 
 // =====================
 // 常用错误码