feat(antigravity): comprehensive enhancements - model mapping, rate limiting, scheduling & ops

Key changes:
- Upgrade model mapping: Opus 4.5 → Opus 4.6-thinking with precise matching
- Unified rate limiting: scope-level → model-level with Redis snapshot sync
- Load-balanced scheduling by call count with smart retry mechanism
- Force cache billing support
- Model identity injection in prompts with leak prevention
- Thinking mode auto-handling (max_tokens/budget_tokens fix)
- Frontend: whitelist mode toggle, model mapping validation, status indicators
- Gemini session fallback with Redis Trie O(L) matching
- Ops: enhanced concurrency monitoring, account availability, retry logic
- Migration scripts: 049-051 for model mapping unification

frontend/src/components/account/BulkEditAccountModal.vue

@@ -925,9 +925,23 @@ const buildUpdatePayload = (): Record<string, unknown> | null => {
 
   if (enableModelRestriction.value) {
     const modelMapping = buildModelMappingObject()
-    if (modelMapping) {
-      credentials.model_mapping = modelMapping
-      credentialsChanged = true
+
+    // 统一使用 model_mapping 字段
+    if (modelRestrictionMode.value === 'whitelist') {
+      if (allowedModels.value.length > 0) {
+        // 白名单模式：将模型转换为 model_mapping 格式（key=value）
+        const mapping: Record<string, string> = {}
+        for (const m of allowedModels.value) {
+          mapping[m] = m
+        }
+        credentials.model_mapping = mapping
+        credentialsChanged = true
+      }
+    } else {
+      if (modelMapping) {
+        credentials.model_mapping = modelMapping
+        credentialsChanged = true
+      }
     }
   }