feat: 增强桌面启动失败提示与测试覆盖

backend/cmd/desktop/dialog_windows.go

@@ -3,17 +3,21 @@
 package main
 
 import (
+	"encoding/base64"
 	"errors"
 	"fmt"
 	"syscall"
+	"unicode/utf16"
 	"unsafe"
-
-	"go.uber.org/zap"
 )
 
 const (
+	mbOK              = 0x00000000
 	mbIconError       = 0x10
 	mbIconInformation = 0x40
+	mbTaskModal       = 0x00002000
+	mbSetForeground   = 0x00010000
+	mbTopMost         = 0x00040000
 )
 
 var (
@@ -25,12 +29,79 @@ var (
 	}
 )
 
-func showError(title, message string) {
-	if err := messageBox(title, message, mbIconError); err != nil {
-		if zapLogger != nil {
-			zapLogger.Warn("显示错误对话框失败", zap.Error(err))
+func platformStartupChannels(runner commandRunner) []promptChannel {
+	return []promptChannel{
+		{
+			name: "windows-toast",
+			available: func() error {
+				_, err := findPowerShell(runner)
+				return err
+			},
+			run: func(req promptRequest) error {
+				name, err := findPowerShell(runner)
+				if err != nil {
+					return err
+				}
+				return runner.Run(promptCommandTimeout, []string{
+					"NEX_TOAST_TITLE=" + req.title,
+					"NEX_TOAST_BODY=" + req.message,
+				}, name, "-NoProfile", "-NonInteractive", "-ExecutionPolicy", "Bypass", "-EncodedCommand", encodePowerShellCommand(windowsToastScript()))
+			},
+		},
+		{
+			name: "windows-messagebox",
+			available: func() error {
+				return messageBoxAvailable()
+			},
+			run: func(req promptRequest) error {
+				return messageBox(req.title, req.message, messageBoxStartupFlags())
+			},
+		},
+	}
+}
+
+func findPowerShell(runner commandRunner) (string, error) {
+	for _, name := range []string{"powershell.exe", "powershell"} {
+		if _, err := runner.LookPath(name); err == nil {
+			return name, nil
 		}
 	}
+	return "", fmt.Errorf("PowerShell 不可用")
+}
+
+func windowsToastScript() string {
+	return `$ErrorActionPreference = 'Stop'
+Add-Type -AssemblyName System.Runtime.WindowsRuntime
+$template = [Windows.UI.Notifications.ToastTemplateType]::ToastText02
+$xml = [Windows.UI.Notifications.ToastNotificationManager]::GetTemplateContent($template)
+$texts = $xml.GetElementsByTagName('text')
+$texts.Item(0).AppendChild($xml.CreateTextNode($env:NEX_TOAST_TITLE)) | Out-Null
+$texts.Item(1).AppendChild($xml.CreateTextNode($env:NEX_TOAST_BODY)) | Out-Null
+$toast = [Windows.UI.Notifications.ToastNotification]::new($xml)
+[Windows.UI.Notifications.ToastNotificationManager]::CreateToastNotifier('Nex').Show($toast)`
+}
+
+func encodePowerShellCommand(script string) string {
+	encoded := utf16.Encode([]rune(script))
+	buf := make([]byte, 0, len(encoded)*2)
+	for _, value := range encoded {
+		buf = append(buf, byte(value), byte(value>>8))
+	}
+	return base64.StdEncoding.EncodeToString(buf)
+}
+
+func messageBoxAvailable() error {
+	if _, err := syscall.UTF16PtrFromString("Nex"); err != nil {
+		return err
+	}
+	if _, err := syscall.UTF16PtrFromString("test"); err != nil {
+		return err
+	}
+	return procMessageBoxW.Find()
+}
+
+func messageBoxStartupFlags() uint {
+	return mbOK | mbIconError | mbTaskModal | mbSetForeground | mbTopMost
 }
 
 func messageBox(title, message string, flags uint) error {