feat: Phase 4 收尾 + Phase 5 打包（首启向导/开机自启/URL scheme 闭环/mac dmg）

Phase 4 剩余三项：
- 首次引导向导（setup/first_run + ui/setup_wizard）：服务自检（含 C# 助手共存
  提示）→ 打印机检测与 HiTi 驱动安装指引（官网链接/重新检测，mac 与 win 文案
  分支，允许无打印机完成）→ 开机自启开关 + scheme 注册；侧栏底部常驻设置区
  （自启开关 + 重新运行引导）
- 开机自启（setup/autostart）：mac 写 LaunchAgent（RunAtLoad 一次性，不用
  KeepAlive——托盘退出不能被拉回）；Windows 走 HKCU Run（reg 命令免 win32 依赖）
- URL scheme 闭环：单实例唤醒端口 38210（setup/single_instance）——zaxprint://
  唤起或重复双击启动第二进程时通知常驻实例弹窗后自退，跨平台一致（弃用
  app_links 的 mac 事件转发不确定性）；Windows 启动时幂等注册 HKCU scheme；
  前端 cardPrinter.ts 加 launchAgent()（zaxprint://open），开卡抽屉离线时显示
  "启动打印助手"按钮，点击唤起后 1s×6 轮询自动上线（biz 前端改动待用户提交）

Phase 5：
- tool/package_macos.sh：构建 → ad-hoc 就地签名（--deep，勿加 --options=runtime：
  hardened runtime 库校验会因 ad-hoc 无 Team ID 拒载 framework，实测踩坑）→
  hdiutil dmg；实测产出 22MB dmg + 签名后冒烟通过
- windows/installer.iss：Inno Setup 安装包脚本（快捷方式/桌面图标/开机自启
  Tasks/zaxprint scheme 注册与卸载清理/HiTi SDK DLL 随 Release 目录打包）

依赖 +url_launcher +shared_preferences；13 测试全过、analyze 零问题。

lib/main.dart

@@ -1,7 +1,11 @@
+import 'dart:io';
+
 import 'package:flutter/material.dart';
 import 'package:window_manager/window_manager.dart';
 
 import 'agent.dart';
+import 'setup/single_instance.dart';
+import 'setup/url_scheme.dart';
 import 'ui/app_shell.dart';
 import 'ui/app_tray.dart';
 
@@ -12,6 +16,17 @@ Future<void> main(List<String> args) async {
   WidgetsFlutterBinding.ensureInitialized();
   await windowManager.ensureInitialized();
 
+  // 单实例：zaxprint:// 唤起或重复双击会启动第二进程——通知常驻实例弹窗后自己退出
+  final isPrimary = await SingleInstance.acquire(
+    onWake: () async {
+      await windowManager.show();
+      await windowManager.focus();
+    },
+  );
+  if (!isPrimary) {
+    exit(0);
+  }
+
   final agent = Agent(AgentOptions.parse(args));
   String? startError;
   try {
@@ -20,6 +35,8 @@ Future<void> main(List<String> args) async {
     startError = '$e';
   }
 
+  await UrlScheme.ensureRegistered(); // Windows 运行时注册 zaxprint://；mac 由 Info.plist 声明
+
   final appTray = AppTray(agent: agent);
   await appTray.start();
 

lib/setup/autostart.dart

@@ -0,0 +1,101 @@
+import 'dart:io';
+
+import '../utils/command_runner.dart';
+
+/// 开机自启：mac 写 LaunchAgent（RunAtLoad 一次性——托盘退出不能被拉回，故不用 KeepAlive）；
+/// Windows 写 HKCU Run 注册表键（reg 命令实现，免 win32 依赖）。
+/// 自启指向当前可执行文件（Platform.resolvedExecutable），以安装位置为准。
+class Autostart {
+  static const macLabel = 'com.zax.desktop-plugin';
+  static const winRunName = 'ZaxDesktopPlugin';
+
+  static bool get isSupported => Platform.isMacOS || Platform.isWindows;
+
+  static String? get _macPlistPath {
+    final home = Platform.environment['HOME'];
+    if (home == null) return null;
+    return '$home/Library/LaunchAgents/$macLabel.plist';
+  }
+
+  /// 自启是否已开启。
+  static Future<bool> isEnabled() async {
+    if (Platform.isMacOS) {
+      final path = _macPlistPath;
+      return path != null && File(path).existsSync();
+    }
+    if (Platform.isWindows) {
+      final r = await runCommand(
+        'reg',
+        ['query', r'HKCU\Software\Microsoft\Windows\CurrentVersion\Run', '/v', winRunName],
+        tolerateExit: true,
+      );
+      return r.contains(winRunName);
+    }
+    return false;
+  }
+
+  /// 开启自启（mac 顺带把 C# 助手的 LaunchAgent 状态返回，供向导提示端口关系）。
+  static Future<void> enable() async {
+    if (Platform.isMacOS) {
+      final path = _macPlistPath;
+      if (path == null) throw StateError('无法定位用户目录');
+      final exe = Platform.resolvedExecutable;
+      await Directory(File(path).parent.path).create(recursive: true);
+      await File(path).writeAsString('''
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>Label</key>
+	<string>$macLabel</string>
+	<key>ProgramArguments</key>
+	<array>
+		<string>$exe</string>
+	</array>
+	<key>RunAtLoad</key>
+	<true/>
+	<key>LaunchOnlyOnce</key>
+	<true/>
+</dict>
+</plist>
+''');
+      return;
+    }
+    if (Platform.isWindows) {
+      final exe = Platform.resolvedExecutable;
+      await runCommand('reg', [
+        'add', r'HKCU\Software\Microsoft\Windows\CurrentVersion\Run',
+        '/v', winRunName, '/t', 'REG_SZ', '/d', '"$exe"', '/f',
+      ]);
+      return;
+    }
+    throw UnsupportedError('当前平台不支持开机自启');
+  }
+
+  static Future<void> disable() async {
+    if (Platform.isMacOS) {
+      final path = _macPlistPath;
+      if (path != null && File(path).existsSync()) {
+        await File(path).delete();
+      }
+      return;
+    }
+    if (Platform.isWindows) {
+      await runCommand(
+        'reg',
+        ['delete', r'HKCU\Software\Microsoft\Windows\CurrentVersion\Run', '/v', winRunName, '/f'],
+        tolerateExit: true, // 不存在时也算关闭成功
+      );
+      return;
+    }
+    throw UnsupportedError('当前平台不支持开机自启');
+  }
+
+  /// C# 版助手的 LaunchAgent 是否在（本机灰度共存提示用；mac only）。
+  static bool get legacyCsharpAgentInstalled {
+    if (!Platform.isMacOS) return false;
+    final home = Platform.environment['HOME'];
+    return home != null &&
+        File('$home/Library/LaunchAgents/com.zax.cardprinteragent.plist').existsSync();
+  }
+}

lib/setup/first_run.dart

@@ -0,0 +1,22 @@
+import 'package:shared_preferences/shared_preferences.dart';
+
+/// 首次引导向导完成标记（shared_preferences 持久化）。
+class FirstRun {
+  static const _key = 'first_run_done';
+
+  static Future<bool> isDone() async {
+    final prefs = await SharedPreferences.getInstance();
+    return prefs.getBool(_key) ?? false;
+  }
+
+  static Future<void> complete() async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setBool(_key, true);
+  }
+
+  /// 重新运行向导（设置入口用）。
+  static Future<void> reset() async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setBool(_key, false);
+  }
+}

lib/setup/single_instance.dart

@@ -0,0 +1,50 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+
+/// 单实例 + 唤醒端口：应用只允许一个常驻实例。
+///
+/// zaxprint:// 唤起或用户再次双击图标时，OS 会启动第二个进程——第二实例连上
+/// 唤醒端口发送 wake 后立即退出，常驻实例收到后把主窗口带到前台。
+/// （比 app_links 的方案更跨平台一致：mac/win 都只依赖回环 socket。）
+class SingleInstance {
+  static const int wakePort = 38210;
+
+  /// 尝试成为主实例。
+  ///
+  /// 返回 true = 本实例是主实例（已开始监听唤醒，[onWake] 在收到唤醒时回调）；
+  /// 返回 false = 已有常驻实例（已通知其显示窗口），调用方应当退出进程。
+  static Future<bool> acquire({void Function()? onWake}) async {
+    try {
+      final server = await ServerSocket.bind(InternetAddress.loopbackIPv4, wakePort);
+      server.listen((socket) {
+        socket
+            .cast<List<int>>()
+            .transform(utf8.decoder)
+            .listen((message) {
+          if (message.contains('wake')) {
+            onWake?.call();
+          }
+        }, onDone: () {
+          socket.destroy();
+        });
+      }, onError: (_) {});
+      return true;
+    } on SocketException {
+      // 端口被占：已有常驻实例，通知它显示窗口
+      try {
+        final socket = await Socket.connect(
+          InternetAddress.loopbackIPv4,
+          wakePort,
+          timeout: const Duration(seconds: 2),
+        );
+        socket.add(utf8.encode('wake'));
+        await socket.flush();
+        await socket.close();
+      } catch (_) {
+        // 唤醒端口被非本应用进程占用等异常：放弃唤醒，按第二实例退出
+      }
+      return false;
+    }
+  }
+}

lib/setup/url_scheme.dart

@@ -0,0 +1,37 @@
+import 'dart:io';
+
+import '../utils/command_runner.dart';
+
+/// zaxprint:// URL scheme 注册：
+/// - macOS：Info.plist CFBundleURLTypes 已声明（构建即生效），无需运行时处理
+/// - Windows：写 HKCU\Software\Classes\zaxprint（用户级，免管理员），App 启动时 ensure
+class UrlScheme {
+  static const scheme = 'zaxprint';
+
+  static bool get needsRuntimeRegister => Platform.isWindows;
+
+  /// Windows：确保 scheme 已注册到当前可执行文件（每次启动幂等调用，路径变了会刷新）。
+  static Future<void> ensureRegistered() async {
+    if (!Platform.isWindows) return;
+    final exe = Platform.resolvedExecutable;
+    final root = r'HKCU\Software\Classes' '\\$scheme';
+    await runCommand('reg', ['add', root, '/ve', '/t', 'REG_SZ', '/d', 'URL:资安信插件助手唤起', '/f']);
+    await runCommand('reg', ['add', root, '/v', 'URL Protocol', '/t', 'REG_SZ', '/d', '', '/f']);
+    await runCommand('reg', [
+      'add', r'HKCU\Software\Classes' '\\$scheme' r'\shell\open\command',
+      '/ve', '/t', 'REG_SZ', '/d', '"$exe" "%1"', '/f',
+    ]);
+  }
+
+  /// Windows：注册是否指向当前可执行文件（向导自检展示用）。
+  static Future<bool> isRegisteredToSelf() async {
+    if (!Platform.isWindows) return true; // mac 由 Info.plist 保证
+    final exe = Platform.resolvedExecutable;
+    final out = await runCommand(
+      'reg',
+      ['query', r'HKCU\Software\Classes' '\\$scheme' r'\shell\open\command', '/ve'],
+      tolerateExit: true,
+    );
+    return out.contains(exe);
+  }
+}

lib/ui/app_shell.dart

@@ -1,7 +1,10 @@
 import 'package:flutter/material.dart';
 
 import '../agent.dart';
+import '../setup/autostart.dart';
+import '../setup/first_run.dart';
 import 'routes.dart';
+import 'setup_wizard.dart';
 
 /// 应用外壳：左侧插件菜单 + 右侧插件页面（菜单项来自路由注册表）。
 class AppShell extends StatefulWidget {
@@ -16,9 +19,50 @@ class AppShell extends StatefulWidget {
 
 class _AppShellState extends State<AppShell> {
   int _selectedIndex = 0;
+  bool _autostart = false;
+  bool _autostartLoaded = false;
 
   Agent get _agent => widget.agent;
 
+  @override
+  void initState() {
+    super.initState();
+    _loadAutostart();
+    _maybeShowWizard();
+  }
+
+  Future<void> _loadAutostart() async {
+    final enabled = await Autostart.isEnabled();
+    if (mounted) {
+      setState(() {
+        _autostart = enabled;
+        _autostartLoaded = true;
+      });
+    }
+  }
+
+  Future<void> _toggleAutostart(bool value) async {
+    setState(() => _autostart = value);
+    try {
+      value ? await Autostart.enable() : await Autostart.disable();
+    } catch (_) {
+      if (mounted) await _loadAutostart(); // 失败回读真实状态
+    }
+  }
+
+  Future<void> _maybeShowWizard() async {
+    if (await FirstRun.isDone()) return;
+    if (!mounted) return;
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted) return;
+      showDialog<void>(
+        context: context,
+        barrierDismissible: false,
+        builder: (_) => SetupWizard(agent: _agent, onFinished: _loadAutostart),
+      );
+    });
+  }
+
   @override
   Widget build(BuildContext context) {
     final scheme = Theme.of(context).colorScheme;
@@ -100,8 +144,43 @@ class _AppShellState extends State<AppShell> {
           ),
 
           Divider(height: 1, thickness: 1, color: scheme.outlineVariant),
+
+          // 设置区：开机自启 + 重新运行引导
           Padding(
-            padding: const EdgeInsets.fromLTRB(16, 10, 16, 12),
+            padding: const EdgeInsets.fromLTRB(8, 6, 8, 0),
+            child: SwitchListTile(
+              dense: true,
+              contentPadding: const EdgeInsets.symmetric(horizontal: 8),
+              value: _autostartLoaded && _autostart,
+              onChanged: Autostart.isSupported ? _toggleAutostart : null,
+              title: Text('开机自动启动', style: Theme.of(context).textTheme.bodySmall),
+              secondary: Icon(Icons.power_settings_new,
+                  size: 18, color: scheme.onSurfaceVariant),
+            ),
+          ),
+          Padding(
+            padding: const EdgeInsets.fromLTRB(16, 0, 8, 4),
+            child: Align(
+              alignment: Alignment.centerLeft,
+              child: TextButton.icon(
+                onPressed: () {
+                  showDialog<void>(
+                    context: context,
+                    barrierDismissible: false,
+                    builder: (_) => SetupWizard(agent: _agent, onFinished: _loadAutostart),
+                  );
+                },
+                icon: const Icon(Icons.restart_alt, size: 14),
+                label: const Text('重新运行引导'),
+                style: TextButton.styleFrom(
+                  textStyle: Theme.of(context).textTheme.bodySmall,
+                  padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
+                ),
+              ),
+            ),
+          ),
+          Padding(
+            padding: const EdgeInsets.fromLTRB(16, 0, 16, 10),
             child: Text(
               'v1.0.0',
               style: Theme.of(context)

lib/ui/setup_wizard.dart

@@ -0,0 +1,296 @@
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+import 'package:url_launcher/url_launcher.dart';
+
+import '../agent.dart';
+import '../server/protocol.dart';
+import '../setup/autostart.dart';
+import '../setup/first_run.dart';
+import '../setup/url_scheme.dart';
+
+/// 首次引导向导：服务自检 → 打印机检测（含驱动引导）→ 自启/唤起配置。
+/// 深色主题对话框，三步 Stepper 风格；允许无打印机完成（纯联调机）。
+class SetupWizard extends StatefulWidget {
+  const SetupWizard({super.key, required this.agent, required this.onFinished});
+
+  final Agent agent;
+  final VoidCallback onFinished;
+
+  /// 便捷入口：未完成过向导时弹出。
+  static Future<void> showIfNeeded(BuildContext context, Agent agent) async {
+    if (await FirstRun.isDone()) return;
+    if (!context.mounted) return;
+    await showDialog<void>(
+      context: context,
+      barrierDismissible: false,
+      builder: (_) => SetupWizard(
+        agent: agent,
+        onFinished: () {},
+      ),
+    );
+  }
+
+  @override
+  State<SetupWizard> createState() => _SetupWizardState();
+}
+
+class _SetupWizardState extends State<SetupWizard> {
+  static const _driverUrl = 'https://www.hiti.com/support/download.aspx?MenuID=72&lang=CN';
+
+  int _step = 0;
+  bool _autostart = true;
+  bool _autostartBusy = false;
+  bool _printerChecking = false;
+  PrinterStatus? _printerStatus;
+
+  Agent get _agent => widget.agent;
+
+  @override
+  void initState() {
+    super.initState();
+    _checkPrinter();
+  }
+
+  Future<void> _checkPrinter() async {
+    setState(() => _printerChecking = true);
+    try {
+      final status = await _agent.backend.getStatus();
+      if (mounted) setState(() => _printerStatus = status);
+    } catch (_) {
+      if (mounted) setState(() => _printerStatus = null);
+    } finally {
+      if (mounted) setState(() => _printerChecking = false);
+    }
+  }
+
+  Future<void> _finish() async {
+    setState(() => _autostartBusy = true);
+    try {
+      if (_autostart && Autostart.isSupported) {
+        await Autostart.enable();
+      }
+      await UrlScheme.ensureRegistered();
+      await FirstRun.complete();
+    } finally {
+      if (mounted) setState(() => _autostartBusy = false);
+    }
+    if (mounted) {
+      Navigator.of(context).pop();
+      widget.onFinished();
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final scheme = Theme.of(context).colorScheme;
+    return Dialog(
+      backgroundColor: scheme.surfaceContainerLow,
+      shape: RoundedRectangleBorder(
+        borderRadius: BorderRadius.circular(14),
+        side: BorderSide(color: scheme.outlineVariant),
+      ),
+      child: ConstrainedBox(
+        constraints: const BoxConstraints(maxWidth: 520),
+        child: Padding(
+          padding: const EdgeInsets.all(24),
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.stretch,
+            children: [
+              _header(scheme),
+              const SizedBox(height: 18),
+              if (_step == 0) _stepWelcome(scheme),
+              if (_step == 1) _stepPrinter(scheme),
+              if (_step == 2) _stepFinish(scheme),
+              const SizedBox(height: 20),
+              _footer(scheme),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+
+  Widget _header(ColorScheme scheme) => Row(
+        children: [
+          Icon(Icons.extension_rounded, color: scheme.primary, size: 26),
+          const SizedBox(width: 10),
+          Text('初次使用引导', style: Theme.of(context).textTheme.titleLarge),
+          const Spacer(),
+          _stepBadge(scheme),
+        ],
+      );
+
+  Widget _stepBadge(ColorScheme scheme) => Row(
+        children: [
+          for (var i = 0; i < 3; i++) ...[
+            Container(
+              width: i == _step ? 18 : 8,
+              height: 8,
+              decoration: BoxDecoration(
+                color: i <= _step ? scheme.primary : scheme.surfaceContainerHighest,
+                borderRadius: BorderRadius.circular(4),
+              ),
+            ),
+            if (i < 2) const SizedBox(width: 6),
+          ],
+        ],
+      );
+
+  // ---------------- Step 0：服务自检 ----------------
+
+  Widget _stepWelcome(ColorScheme scheme) => Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text('资安信插件助手在本机为管理端网页提供打印等桌面能力，安装完成后保持后台运行即可，无需日常操作。',
+              style: Theme.of(context).textTheme.bodyMedium),
+          const SizedBox(height: 14),
+          _checkRow(
+            scheme,
+            ok: _agent.port != null,
+            okText: '本机服务运行中${_agent.port != null ? "（127.0.0.1:${_agent.port}）" : ""}',
+            badText: '本机服务未启动（可能是端口被占用，请重启应用）',
+          ),
+          if (Autostart.legacyCsharpAgentInstalled) ...[
+            const SizedBox(height: 8),
+            Container(
+              padding: const EdgeInsets.all(10),
+              decoration: BoxDecoration(
+                color: scheme.surfaceContainerHighest,
+                borderRadius: BorderRadius.circular(8),
+              ),
+              child: Text(
+                '检测到旧版打印助手（C# 版）在本机自启。两者协议兼容可并存，'
+                '如需完全切换到本应用，可在终端执行：\n'
+                'launchctl unload ~/Library/LaunchAgents/com.zax.cardprinteragent.plist',
+                style: Theme.of(context).textTheme.bodySmall?.copyWith(height: 1.5),
+              ),
+            ),
+          ],
+        ],
+      );
+
+  // ---------------- Step 1：打印机检测 ----------------
+
+  Widget _stepPrinter(ColorScheme scheme) {
+    final s = _printerStatus;
+    final ready = s != null && s.online;
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        _checkRow(
+          scheme,
+          ok: ready,
+          loading: _printerChecking,
+          okText: '打印机就绪${s != null && s.model.isNotEmpty ? "（${s.model}）" : ""}',
+          badText: s == null ? '未检测到打印队列' : (s.statusText.isEmpty ? '打印机未就绪' : s.statusText),
+        ),
+        if (!ready) ...[
+          const SizedBox(height: 12),
+          Text(
+            Platform.isMacOS
+                ? '安装步骤：① 打开 HiTi 官网下载 macOS 驱动（HiTiCardTypeMacDrivers dmg），双击安装里面的 pkg；② USB 连接打印机并开机；③ 系统设置 → 打印机与扫描仪 确认出现 HiTi 打印机；④ 回到这里点「重新检测」。'
+                : 'Windows 打印站：打开 HiTi 官网下载 CS-2xx Windows 驱动并安装，USB 连接打印机；本应用也支持免驱动的 SDK 直连模式，装完驱动或接好打印机后点「重新检测」。',
+            style: Theme.of(context).textTheme.bodySmall?.copyWith(height: 1.6),
+          ),
+          const SizedBox(height: 8),
+          Align(
+            alignment: Alignment.centerLeft,
+            child: TextButton.icon(
+              onPressed: () => launchUrl(Uri.parse(_driverUrl)),
+              icon: const Icon(Icons.open_in_new, size: 14),
+              label: const Text('打开 HiTi 驱动下载页'),
+            ),
+          ),
+          const SizedBox(height: 4),
+          TextButton.icon(
+            onPressed: _printerChecking ? null : _checkPrinter,
+            icon: const Icon(Icons.refresh, size: 16),
+            label: const Text('重新检测'),
+          ),
+        ] else ...[
+          const SizedBox(height: 12),
+          Text('打印机已连接，可以正常接收管理端提交的卡面打印。',
+              style: Theme.of(context).textTheme.bodySmall),
+        ],
+      ],
+    );
+  }
+
+  // ---------------- Step 2：完成配置 ----------------
+
+  Widget _stepFinish(ColorScheme scheme) => Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          SwitchListTile(
+            contentPadding: EdgeInsets.zero,
+            value: _autostart,
+            onChanged: Autostart.isSupported
+                ? (v) => setState(() => _autostart = v)
+                : null,
+            title: const Text('开机自动启动'),
+            subtitle: Text(
+              Autostart.isSupported ? '登录系统后自动在后台运行（可在左侧菜单底部随时修改）' : '当前平台不支持',
+              style: Theme.of(context).textTheme.bodySmall,
+            ),
+          ),
+          const SizedBox(height: 6),
+          _checkRow(
+            scheme,
+            ok: true,
+            okText: '网页唤起支持（zaxprint:// 协议）已启用',
+            badText: '',
+          ),
+          const SizedBox(height: 8),
+          Text(
+            '全部完成。关闭窗口将最小化到托盘，服务持续运行；退出请通过托盘菜单。',
+            style: Theme.of(context).textTheme.bodySmall,
+          ),
+        ],
+      );
+
+  // ---------------- 公共组件 ----------------
+
+  Widget _checkRow(ColorScheme scheme,
+      {required bool ok, required String okText, required String badText, bool loading = false}) {
+    final color = ok ? scheme.primary : const Color(0xFFD97706);
+    return Row(
+      children: [
+        if (loading)
+          const SizedBox(
+              width: 18, height: 18, child: CircularProgressIndicator(strokeWidth: 2))
+        else
+          Icon(ok ? Icons.check_circle : Icons.info_outline, size: 18, color: color),
+        const SizedBox(width: 8),
+        Expanded(
+          child: Text(
+            ok ? okText : badText,
+            style: Theme.of(context).textTheme.bodyMedium?.copyWith(color: color),
+          ),
+        ),
+      ],
+    );
+  }
+
+  Widget _footer(ColorScheme scheme) => Row(
+        children: [
+          if (_step > 0)
+            TextButton(
+              onPressed: () => setState(() => _step--),
+              child: const Text('上一步'),
+            ),
+          const Spacer(),
+          if (_step < 2)
+            FilledButton(
+              onPressed: () => setState(() => _step++),
+              child: Text(_step == 0 ? '下一步' : '跳过，下一步'),
+            )
+          else
+            FilledButton(
+              onPressed: _autostartBusy ? null : _finish,
+              child: const Text('完成'),
+            ),
+        ],
+      );
+}