fix(账号管理): 调度批量结果明细与刷新优化

补充批量调度返回 success_ids/failed_ids 并增加合约/单测

前端加入降级处理与部分失败提示，表格行使用稳定 key

测试: make test-frontend

测试: go test ./internal/service -run BulkUpdateAccounts -tags=unit

测试: go test ./internal/server -run APIContracts -tags=unit

frontend/src/api/admin/accounts.ts

@@ -275,11 +275,15 @@ export async function bulkUpdate(
 ): Promise<{
   success: number
   failed: number
+  success_ids?: number[]
+  failed_ids?: number[]
   results: Array<{ account_id: number; success: boolean; error?: string }>
-}> {
+  }> {
   const { data } = await apiClient.post<{
     success: number
     failed: number
+    success_ids?: number[]
+    failed_ids?: number[]
     results: Array<{ account_id: number; success: boolean; error?: string }>
   }>('/admin/accounts/bulk-update', {
     account_ids: accountIds,