Remove redundant Darwin tray stub (#1694)

web/backend/tray_stub_darwin_nocgo.go

@@ -1,32 +0,0 @@
-//go:build darwin && !cgo
-
-package main
-
-import (
-	"context"
-	"os"
-	"os/signal"
-	"syscall"
-	"time"
-
-	"github.com/sipeed/picoclaw/pkg/logger"
-)
-
-func runTray() {
-	logger.Infof("System tray is unavailable in darwin builds without cgo; running without tray")
-
-	if !*noBrowser {
-		go func() {
-			time.Sleep(browserDelay)
-			if err := openBrowser(); err != nil {
-				logger.Errorf("Warning: Failed to auto-open browser: %v", err)
-			}
-		}()
-	}
-
-	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
-	defer stop()
-
-	<-ctx.Done()
-	shutdownApp()
-}