merge: 合并main分支最新改动

解决冲突：
- backend/internal/config/config.go: 合并Ops和Dashboard配置
- backend/internal/server/api_contract_test.go: 合并handler初始化
- backend/internal/service/openai_gateway_service.go: 保留Ops错误追踪逻辑
- backend/internal/service/wire.go: 合并Ops和APIKeyAuth provider

主要合并内容：
- Dashboard缓存和预聚合功能
- API Key认证缓存优化
- Codex转换支持
- 使用日志分区表

backend/internal/server/routes/admin.go

@@ -130,6 +130,7 @@ func registerDashboardRoutes(admin *gin.RouterGroup, h *handler.Handlers) {
 		dashboard.GET("/users-trend", h.Admin.Dashboard.GetUserUsageTrend)
 		dashboard.POST("/users-usage", h.Admin.Dashboard.GetBatchUsersUsage)
 		dashboard.POST("/api-keys-usage", h.Admin.Dashboard.GetBatchAPIKeysUsage)
+		dashboard.POST("/aggregation/backfill", h.Admin.Dashboard.BackfillAggregation)
 	}
 }