feat: 错误透传规则支持 skip_monitoring 跳过运维监控记录

在每条错误透传规则上新增 skip_monitoring 选项，开启后匹配该规则的错误
不会被记录到 ops_error_logs，减少监控噪音。默认关闭，不影响现有规则。

backend/internal/handler/ops_error_logger.go

@@ -544,6 +544,13 @@ func OpsErrorLoggerMiddleware(ops *service.OpsService) gin.HandlerFunc {
 		body := w.buf.Bytes()
 		parsed := parseOpsErrorResponse(body)
 
+		// Skip logging if a passthrough rule with skip_monitoring=true matched.
+		if v, ok := c.Get(service.OpsSkipPassthroughKey); ok {
+			if skip, _ := v.(bool); skip {
+				return
+			}
+		}
+
 		// Skip logging if the error should be filtered based on settings
 		if shouldSkipOpsErrorLog(c.Request.Context(), ops, parsed.Message, string(body), c.Request.URL.Path) {
 			return