fix: register shutdown signals before startup

main.go

@@ -83,6 +83,10 @@ func run() error {
 	}
 	log.Printf("[main] filter mode=%s patterns=%d", filter.Mode, len(filter.Patterns))
 
+	stop := make(chan os.Signal, 1)
+	signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
+	defer signal.Stop(stop)
+
 	rootCtx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
@@ -114,10 +118,7 @@ func run() error {
 		serverErr <- srv.ListenAndServe()
 	}()
 
-	stop := make(chan os.Signal, 1)
-	signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
 	runErr := waitForShutdown(stop, serverErr)
-	signal.Stop(stop)
 
 	// HTTP、升级连接、日志排空和数据库共享同一个关闭总预算。
 	shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 30*time.Second)