feat: 增强桌面启动失败提示与测试覆盖

backend/cmd/desktop/dialog_darwin_test.go

@@ -0,0 +1,46 @@
+//go:build darwin
+
+package main
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestDarwinStartupChannelsBuildNotificationAndAlert(t *testing.T) {
+	runner := &fakeCommandRunner{paths: map[string]bool{"osascript": true}}
+	channels := platformStartupChannels(runner)
+	if len(channels) != 2 {
+		t.Fatalf("macOS 应有 notification 和 alert 两级通道，实际: %d", len(channels))
+	}
+
+	req := promptRequest{title: "Nex 启动失败", subtitle: "config", message: "路径 C:\\tmp 包含 \"quote\""}
+	for _, channel := range channels {
+		if err := channel.available(); err != nil {
+			t.Fatalf("通道 %s 应可用: %v", channel.name, err)
+		}
+		if err := channel.run(req); err != nil {
+			t.Fatalf("通道 %s 执行失败: %v", channel.name, err)
+		}
+	}
+
+	if len(runner.calls) != 2 {
+		t.Fatalf("应执行两次 osascript，实际: %d", len(runner.calls))
+	}
+	if runner.calls[0].name != "osascript" || runner.calls[0].args[0] != "-e" {
+		t.Fatalf("notification 命令参数错误: %#v", runner.calls[0])
+	}
+	if script := runner.calls[0].args[1]; !strings.Contains(script, "display notification") || !strings.Contains(script, `\\tmp`) || !strings.Contains(script, `\"quote\"`) {
+		t.Fatalf("notification AppleScript 未正确构造或转义: %s", script)
+	}
+	if script := runner.calls[1].args[1]; !strings.Contains(script, "display alert") || !strings.Contains(script, "as critical") {
+		t.Fatalf("alert AppleScript 未使用 critical 告警: %s", script)
+	}
+}
+
+func TestEscapeAppleScript(t *testing.T) {
+	got := escapeAppleScript(`C:\tmp "quote"`)
+	if !strings.Contains(got, `C:\\tmp`) || !strings.Contains(got, `\"quote\"`) {
+		t.Fatalf("AppleScript 转义结果错误: %s", got)
+	}
+}