feat(i18n): 完成全量 UI 文本国际化，替换所有硬编码中文为 AppLocalizations 调用

- core/localization: 新增约 60 个翻译键（含参数化方法），中英双语覆盖
- shared/widgets: CommonDialog 默认参数国际化
- features/home: 完成页操作步骤指引、状态栏串口连接状态、程序列表状态标签
- features/programs: 表头状态列、表单验证提示、导入/模板操作反馈、删除确认（参数化）
- features/program_detail: 步骤列表/表单标题、删除确认、速度档位显示（参数化）
- features/device: run_state_provider 错误消息改为错误码
- features/settings: 升级页、密码面板、语言面板、U盘导入面板、串口配置面板全部替换

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

lib/features/settings/widgets/serial_config_panel.dart

@@ -3,6 +3,7 @@ import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:usb_serial/usb_serial.dart';
 
+import '../../../core/localization/app_localizations.dart';
 import '../../../core/theme/app_theme.dart';
 import '../../device/models/serial_config.dart';
 import '../../device/providers/serial_provider.dart';
@@ -48,14 +49,14 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
     } catch (e) {
       if (!mounted) return;
       setState(() => _loadingDevices = false);
-      _showSnack('扫描设备失败: $e', AppTheme.errorColor);
+      _showSnack('${AppLocalizations.of(context)?.scanFailed ?? '扫描设备失败'}: $e', AppTheme.errorColor);
     }
   }
 
   Future<void> _connect() async {
     final device = _selectedDevice;
     if (device == null) {
-      _showSnack('请先选择串口设备', AppTheme.warningColor);
+      _showSnack(AppLocalizations.of(context)?.selectSerialFirst ?? '请先选择串口设备', AppTheme.warningColor);
       return;
     }
     setState(() => _operating = true);
@@ -65,7 +66,7 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
     if (!mounted) return;
     setState(() => _operating = false);
     _showSnack(
-      ok ? '连接成功' : '连接失败: ${service.lastError ?? "未知错误"}',
+      ok ? (AppLocalizations.of(context)?.connectSuccess ?? '连接成功') : ('${AppLocalizations.of(context)?.connectFailed ?? '连接失败'}: ${service.lastError ?? (AppLocalizations.of(context)?.unknownError ?? '未知错误')}'),
       ok ? AppTheme.successColor : AppTheme.errorColor,
     );
   }
@@ -76,13 +77,13 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
     await service.disconnect();
     if (!mounted) return;
     setState(() => _operating = false);
-    _showSnack('已断开串口', AppTheme.infoColor);
+    _showSnack(AppLocalizations.of(context)?.disconnected ?? '已断开串口', AppTheme.infoColor);
   }
 
   Future<void> _testConnection() async {
     final service = ref.read(serialPortServiceProvider);
     if (!service.isConnected) {
-      _showSnack('请先连接串口', AppTheme.warningColor);
+      _showSnack(AppLocalizations.of(context)?.connectFirst ?? '请先连接串口', AppTheme.warningColor);
       return;
     }
     final msgService = ref.read(deviceMessageServiceProvider);
@@ -94,7 +95,7 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
     ));
     if (!mounted) return;
     _showSnack(
-      ok ? '已发送 device_info 查询' : '发送失败',
+      ok ? (AppLocalizations.of(context)?.sendTestFrame ?? '已发送测试查询') : (AppLocalizations.of(context)?.connectFailed ?? '发送失败'),
       ok ? AppTheme.successColor : AppTheme.errorColor,
     );
   }
@@ -107,25 +108,26 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
 
   @override
   Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
     final config = ref.watch(serialConfigProvider);
     final state = ref.watch(serialPortServiceProvider).state;
     return ListView(
       padding: const EdgeInsets.all(0),
       children: [
-        _buildStatusCard(state),
+        _buildStatusCard(state, l10n),
         const SizedBox(height: 16),
-        _buildDeviceCard(),
+        _buildDeviceCard(l10n),
         const SizedBox(height: 16),
-        _buildParamCard(config),
+        _buildParamCard(config, l10n),
         const SizedBox(height: 16),
-        _buildActionRow(),
+        _buildActionRow(l10n),
       ],
     );
   }
 
   // -- 状态卡 ----------------------------------------------------------
 
-  Widget _buildStatusCard(SerialConnectionState state) {
+  Widget _buildStatusCard(SerialConnectionState state, AppLocalizations? l10n) {
     final color = switch (state) {
       SerialConnectionState.connected => AppTheme.successColor,
       SerialConnectionState.connecting => AppTheme.warningColor,
@@ -133,10 +135,10 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
       SerialConnectionState.disconnected => AppTheme.idleColor,
     };
     final text = switch (state) {
-      SerialConnectionState.connected => '已连接',
-      SerialConnectionState.connecting => '连接中...',
-      SerialConnectionState.error => '错误',
-      SerialConnectionState.disconnected => '未连接',
+      SerialConnectionState.connected => l10n?.serialConnected ?? '已连接',
+      SerialConnectionState.connecting => l10n?.serialConnecting ?? '连接中...',
+      SerialConnectionState.error => l10n?.serialError ?? '错误',
+      SerialConnectionState.disconnected => l10n?.serialDisconnected ?? '未连接',
     };
     return Container(
       padding: const EdgeInsets.all(16),
@@ -153,7 +155,7 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
             decoration: BoxDecoration(color: color, shape: BoxShape.circle),
           ),
           const SizedBox(width: 12),
-          Text('串口状态: $text',
+          Text('${l10n?.serialStatus ?? '串口状态'}: $text',
               style: TextStyle(
                 color: AppTheme.textPrimary,
                 fontSize: 16,
@@ -166,13 +168,13 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
 
   // -- 设备列表 --------------------------------------------------------
 
-  Widget _buildDeviceCard() {
+  Widget _buildDeviceCard(AppLocalizations? l10n) {
     return _SectionCard(
-      title: '可用串口设备',
+      title: l10n?.availableSerialDevices ?? '可用串口设备',
       trailing: TextButton.icon(
         onPressed: _loadingDevices ? null : _refreshDevices,
         icon: const Icon(Icons.refresh, size: 18),
-        label: const Text('刷新'),
+        label: Text(l10n?.refresh ?? '刷新'),
       ),
       child: _loadingDevices
           ? const Padding(
@@ -190,16 +192,17 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
   }
 
   Widget _buildEmptyDevice() {
+    final l10n = AppLocalizations.of(context);
     return Padding(
       padding: const EdgeInsets.symmetric(vertical: 24, horizontal: 8),
       child: Column(
         children: [
           Icon(Icons.usb_off, size: 40, color: AppTheme.idleColor),
           const SizedBox(height: 8),
-          Text('未检测到 USB 串口设备',
+          Text(l10n?.noSerialDevice ?? '未检测到 USB 串口设备',
               style: TextStyle(color: AppTheme.textSecondary)),
           const SizedBox(height: 4),
-          Text('请确认下位机已上电并通过 USB 接入设备',
+          Text(l10n?.serialDeviceHint ?? '请确认下位机已上电并通过 USB 接入设备',
               style: TextStyle(color: AppTheme.textSecondary, fontSize: 12)),
         ],
       ),
@@ -255,45 +258,45 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
 
   // -- 参数配置 --------------------------------------------------------
 
-  Widget _buildParamCard(SerialConfig config) {
+  Widget _buildParamCard(SerialConfig config, AppLocalizations? l10n) {
     return _SectionCard(
-      title: '串口参数',
+      title: l10n?.serialParams ?? '串口参数',
       child: Column(
         children: [
-          _baudRateRow(config),
+          _baudRateRow(config, l10n),
           _dropdownRow<int>(
-            label: '数据位',
+            label: l10n?.dataBits ?? '数据位',
             value: config.dataBits,
             options: const [5, 6, 7, 8],
             display: (v) => '$v',
             onChanged: (v) => _updateConfig((c) => c.copyWith(dataBits: v)),
           ),
           _dropdownRow<int>(
-            label: '停止位',
+            label: l10n?.stopBits ?? '停止位',
             value: config.stopBits,
             options: const [1, 2],
             display: (v) => '$v',
             onChanged: (v) => _updateConfig((c) => c.copyWith(stopBits: v)),
           ),
           _dropdownRow<SerialParity>(
-            label: '校验位',
+            label: l10n?.parity ?? '校验位',
             value: config.parity,
             options: SerialParity.values,
             display: (v) => switch (v) {
-              SerialParity.none => '无',
-              SerialParity.odd => '奇',
-              SerialParity.even => '偶',
-              SerialParity.mark => '标记',
-              SerialParity.space => '空',
+              SerialParity.none => l10n?.parityNone ?? '无',
+              SerialParity.odd => l10n?.parityOdd ?? '奇',
+              SerialParity.even => l10n?.parityEven ?? '偶',
+              SerialParity.mark => l10n?.parityMark ?? '标记',
+              SerialParity.space => l10n?.paritySpace ?? '空',
             },
             onChanged: (v) => _updateConfig((c) => c.copyWith(parity: v)),
           ),
           _dropdownRow<SerialFlowControl>(
-            label: '流控',
+            label: l10n?.flowControl ?? '流控',
             value: config.flowControl,
             options: SerialFlowControl.values,
             display: (v) => switch (v) {
-              SerialFlowControl.none => '无',
+              SerialFlowControl.none => l10n?.parityNone ?? '无',
               SerialFlowControl.rtsCts => 'RTS/CTS',
               SerialFlowControl.xonXoff => 'XON/XOFF',
               SerialFlowControl.dtrDsr => 'DTR/DSR',
@@ -304,7 +307,7 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
           Align(
             alignment: Alignment.centerRight,
             child: Text(
-              '参数修改后自动保存',
+              l10n?.autoSaveParams ?? '参数修改后自动保存',
               style: TextStyle(color: AppTheme.textSecondary, fontSize: 12),
             ),
           ),
@@ -313,7 +316,7 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
     );
   }
 
-  Widget _baudRateRow(SerialConfig config) {
+  Widget _baudRateRow(SerialConfig config, AppLocalizations? l10n) {
     final ctrl = TextEditingController(text: config.baudRate.toString());
     return Padding(
       padding: const EdgeInsets.symmetric(vertical: 8),
@@ -322,7 +325,7 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
           SizedBox(
               width: 80,
               child:
-                  Text('波特率', style: TextStyle(color: AppTheme.textPrimary))),
+                  Text(l10n?.baudRate ?? '波特率', style: TextStyle(color: AppTheme.textPrimary))),
           const SizedBox(width: 12),
           SizedBox(
             width: 140,
@@ -425,7 +428,7 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
 
   // -- 操作按钮 --------------------------------------------------------
 
-  Widget _buildActionRow() {
+  Widget _buildActionRow(AppLocalizations? l10n) {
     return Wrap(
       spacing: 12,
       runSpacing: 12,
@@ -433,19 +436,19 @@ class _SerialConfigPanelState extends ConsumerState<SerialConfigPanel> {
         ElevatedButton.icon(
           onPressed: _operating ? null : _connect,
           icon: const Icon(Icons.link),
-          label: const Text('连接'),
+          label: Text(l10n?.connect ?? '连接'),
         ),
         ElevatedButton.icon(
           onPressed:
               _operating ? null : _disconnect,
           style: ElevatedButton.styleFrom(backgroundColor: AppTheme.errorColor),
           icon: const Icon(Icons.link_off),
-          label: const Text('断开'),
+          label: Text(l10n?.disconnect ?? '断开'),
         ),
         OutlinedButton.icon(
           onPressed: _operating ? null : _testConnection,
           icon: const Icon(Icons.send),
-          label: const Text('发送测试帧'),
+          label: Text(l10n?.sendTestFrame ?? '发送测试帧'),
         ),
       ],
     );