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/programs/widgets/program_form_dialog.dart

@@ -71,14 +71,14 @@ class _ProgramFormDialogState extends ConsumerState<ProgramFormDialog> {
                 controller: _codeController,
                 decoration: InputDecoration(
                   labelText: l10n?.programCode ?? '编号',
-                  hintText: '例如: P001',
+                  hintText: l10n?.hintCode ?? '例如: P001',
                   border: OutlineInputBorder(
                     borderRadius: BorderRadius.circular(8),
                   ),
                 ),
                 validator: (value) {
                   if (value == null || value.trim().isEmpty) {
-                    return '请输入编号';
+                    return l10n?.enterCode ?? '请输入编号';
                   }
                   return null;
                 },
@@ -90,14 +90,14 @@ class _ProgramFormDialogState extends ConsumerState<ProgramFormDialog> {
                 controller: _nameController,
                 decoration: InputDecoration(
                   labelText: l10n?.programName ?? '名称',
-                  hintText: '请输入程序名称',
+                  hintText: l10n?.hintProgramName ?? '请输入程序名称',
                   border: OutlineInputBorder(
                     borderRadius: BorderRadius.circular(8),
                   ),
                 ),
                 validator: (value) {
                   if (value == null || value.trim().isEmpty) {
-                    return '请输入名称';
+                    return l10n?.enterName ?? '请输入名称';
                   }
                   return null;
                 },
@@ -140,7 +140,7 @@ class _ProgramFormDialogState extends ConsumerState<ProgramFormDialog> {
               Row(
                 children: [
                   Text(
-                    '状态',
+                    l10n?.status ?? '状态',
                     style: TextStyle(color: AppTheme.textPrimary),
                   ),
                   const Spacer(),
@@ -154,7 +154,7 @@ class _ProgramFormDialogState extends ConsumerState<ProgramFormDialog> {
                     activeColor: AppTheme.successColor,
                   ),
                   Text(
-                    _isEnabled ? '启用' : '停用',
+                    _isEnabled ? (l10n?.enabled ?? '启用') : (l10n?.disabled ?? '停用'),
                     style: TextStyle(
                       color: _isEnabled ? AppTheme.successColor : AppTheme.idleColor,
                     ),
@@ -222,7 +222,7 @@ class _ProgramFormDialogState extends ConsumerState<ProgramFormDialog> {
     } else {
       ScaffoldMessenger.of(context).showSnackBar(
         SnackBar(
-          content: Text('保存失败，请检查编号是否重复'),
+          content: Text(l10n?.saveFailed ?? '保存失败，请检查编号是否重复'),
           backgroundColor: AppTheme.errorColor,
         ),
       );