fix(backend): add no-cgo tray fallback for darwin and freebsd (#1691)

* refactor(backend): add darwin no-cgo tray fallback

* fix(release): stub tray for freebsd builds without cgo

web/backend/systray.go

@@ -1,4 +1,4 @@
-//go:build !darwin || cgo
+//go:build (!darwin && !freebsd) || cgo
 
 package main
 

web/backend/tray_stub_nocgo.go

@@ -0,0 +1,33 @@
+//go:build (darwin || freebsd) && !cgo
+
+package main
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"runtime"
+	"syscall"
+	"time"
+
+	"github.com/sipeed/picoclaw/pkg/logger"
+)
+
+func runTray() {
+	logger.Infof("System tray is unavailable in %s builds without cgo; running without tray", runtime.GOOS)
+
+	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()
+}