feat(i18n): localize settings + search screens

Extend the en/zh localization to the two screens reached from the home
app bar (the "全都用 + 多语言" ask):
- settings: title, theme-mode segments (System/Light/Dark), seed-color
  description, color-picker + clear-data dialogs.
- search: hint, error, empty/no-results states, Notes/Documents section
  headers, page label.

New ARB keys regenerated; l10n_test now asserts the new keys resolve in
both English and Chinese.

flutter analyze: 0 issues. l10n_test: 3/3.

lib/l10n/app_en.arb

@@ -15,6 +15,31 @@
   "openInSplitView": "Open in Split View",
   "splitViewSubtitle": "PDF reference + scratchpad",
   "removeDocument": "Remove document",
+  "ok": "OK",
+  "pickColor": "Pick a color",
+  "clearSettingsTitle": "Clear all local settings?",
+  "clear": "Clear",
+  "settingsReset": "Settings reset to defaults",
+  "themeSystem": "System",
+  "themeLight": "Light",
+  "themeDark": "Dark",
+  "seedColorDesc": "Seed color for Material 3 theme",
+  "searchHint": "Search notes and documents...",
+  "searchError": "Search error: {error}",
+  "@searchError": {
+    "placeholders": { "error": { "type": "String" } }
+  },
+  "noResultsFor": "No results for \"{query}\"",
+  "@noResultsFor": {
+    "placeholders": { "query": { "type": "String" } }
+  },
+  "typeToSearch": "Type to search your notes and documents",
+  "sectionNotes": "Notes",
+  "sectionDocuments": "Documents",
+  "pageLabel": "Page {page}",
+  "@pageLabel": {
+    "placeholders": { "page": { "type": "int" } }
+  },
   "processingPptx": "Processing PPTX...",
   "processingPresentation": "Processing presentation...",
   "couldNotOpenPresentation": "Could not open presentation.",

lib/l10n/app_localizations.dart

@@ -188,6 +188,102 @@ abstract class AppLocalizations {
   /// **'Remove document'**
   String get removeDocument;
 
+  /// No description provided for @ok.
+  ///
+  /// In en, this message translates to:
+  /// **'OK'**
+  String get ok;
+
+  /// No description provided for @pickColor.
+  ///
+  /// In en, this message translates to:
+  /// **'Pick a color'**
+  String get pickColor;
+
+  /// No description provided for @clearSettingsTitle.
+  ///
+  /// In en, this message translates to:
+  /// **'Clear all local settings?'**
+  String get clearSettingsTitle;
+
+  /// No description provided for @clear.
+  ///
+  /// In en, this message translates to:
+  /// **'Clear'**
+  String get clear;
+
+  /// No description provided for @settingsReset.
+  ///
+  /// In en, this message translates to:
+  /// **'Settings reset to defaults'**
+  String get settingsReset;
+
+  /// No description provided for @themeSystem.
+  ///
+  /// In en, this message translates to:
+  /// **'System'**
+  String get themeSystem;
+
+  /// No description provided for @themeLight.
+  ///
+  /// In en, this message translates to:
+  /// **'Light'**
+  String get themeLight;
+
+  /// No description provided for @themeDark.
+  ///
+  /// In en, this message translates to:
+  /// **'Dark'**
+  String get themeDark;
+
+  /// No description provided for @seedColorDesc.
+  ///
+  /// In en, this message translates to:
+  /// **'Seed color for Material 3 theme'**
+  String get seedColorDesc;
+
+  /// No description provided for @searchHint.
+  ///
+  /// In en, this message translates to:
+  /// **'Search notes and documents...'**
+  String get searchHint;
+
+  /// No description provided for @searchError.
+  ///
+  /// In en, this message translates to:
+  /// **'Search error: {error}'**
+  String searchError(String error);
+
+  /// No description provided for @noResultsFor.
+  ///
+  /// In en, this message translates to:
+  /// **'No results for \"{query}\"'**
+  String noResultsFor(String query);
+
+  /// No description provided for @typeToSearch.
+  ///
+  /// In en, this message translates to:
+  /// **'Type to search your notes and documents'**
+  String get typeToSearch;
+
+  /// No description provided for @sectionNotes.
+  ///
+  /// In en, this message translates to:
+  /// **'Notes'**
+  String get sectionNotes;
+
+  /// No description provided for @sectionDocuments.
+  ///
+  /// In en, this message translates to:
+  /// **'Documents'**
+  String get sectionDocuments;
+
+  /// No description provided for @pageLabel.
+  ///
+  /// In en, this message translates to:
+  /// **'Page {page}'**
+  String pageLabel(int page);
+
   /// No description provided for @processingPptx.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_en.dart

@@ -53,6 +53,60 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get removeDocument => 'Remove document';
 
+  @override
+  String get ok => 'OK';
+
+  @override
+  String get pickColor => 'Pick a color';
+
+  @override
+  String get clearSettingsTitle => 'Clear all local settings?';
+
+  @override
+  String get clear => 'Clear';
+
+  @override
+  String get settingsReset => 'Settings reset to defaults';
+
+  @override
+  String get themeSystem => 'System';
+
+  @override
+  String get themeLight => 'Light';
+
+  @override
+  String get themeDark => 'Dark';
+
+  @override
+  String get seedColorDesc => 'Seed color for Material 3 theme';
+
+  @override
+  String get searchHint => 'Search notes and documents...';
+
+  @override
+  String searchError(String error) {
+    return 'Search error: $error';
+  }
+
+  @override
+  String noResultsFor(String query) {
+    return 'No results for \"$query\"';
+  }
+
+  @override
+  String get typeToSearch => 'Type to search your notes and documents';
+
+  @override
+  String get sectionNotes => 'Notes';
+
+  @override
+  String get sectionDocuments => 'Documents';
+
+  @override
+  String pageLabel(int page) {
+    return 'Page $page';
+  }
+
   @override
   String get processingPptx => 'Processing PPTX...';
 

lib/l10n/app_localizations_zh.dart

@@ -53,6 +53,60 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get removeDocument => '移除文档';
 
+  @override
+  String get ok => '确定';
+
+  @override
+  String get pickColor => '选择颜色';
+
+  @override
+  String get clearSettingsTitle => '清除所有本地设置？';
+
+  @override
+  String get clear => '清除';
+
+  @override
+  String get settingsReset => '设置已恢复默认';
+
+  @override
+  String get themeSystem => '跟随系统';
+
+  @override
+  String get themeLight => '浅色';
+
+  @override
+  String get themeDark => '深色';
+
+  @override
+  String get seedColorDesc => 'Material 3 主题种子色';
+
+  @override
+  String get searchHint => '搜索笔记和文档…';
+
+  @override
+  String searchError(String error) {
+    return '搜索出错：$error';
+  }
+
+  @override
+  String noResultsFor(String query) {
+    return '没有“$query”的结果';
+  }
+
+  @override
+  String get typeToSearch => '输入以搜索你的笔记和文档';
+
+  @override
+  String get sectionNotes => '笔记';
+
+  @override
+  String get sectionDocuments => '文档';
+
+  @override
+  String pageLabel(int page) {
+    return '第 $page 页';
+  }
+
   @override
   String get processingPptx => '正在处理 PPTX…';
 

lib/l10n/app_zh.arb

@@ -15,6 +15,22 @@
   "openInSplitView": "分屏打开",
   "splitViewSubtitle": "PDF 参考 + 草稿纸",
   "removeDocument": "移除文档",
+  "ok": "确定",
+  "pickColor": "选择颜色",
+  "clearSettingsTitle": "清除所有本地设置？",
+  "clear": "清除",
+  "settingsReset": "设置已恢复默认",
+  "themeSystem": "跟随系统",
+  "themeLight": "浅色",
+  "themeDark": "深色",
+  "seedColorDesc": "Material 3 主题种子色",
+  "searchHint": "搜索笔记和文档…",
+  "searchError": "搜索出错：{error}",
+  "noResultsFor": "没有“{query}”的结果",
+  "typeToSearch": "输入以搜索你的笔记和文档",
+  "sectionNotes": "笔记",
+  "sectionDocuments": "文档",
+  "pageLabel": "第 {page} 页",
   "processingPptx": "正在处理 PPTX…",
   "processingPresentation": "正在处理演示文稿…",
   "couldNotOpenPresentation": "无法打开演示文稿。",

lib/screens/search_screen.dart

@@ -3,6 +3,7 @@ import 'dart:async';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import '../l10n/app_localizations.dart';
 import '../models/note.dart';
 import '../providers/search_provider.dart';
 import 'note_editor_screen.dart';
@@ -42,16 +43,17 @@ class _SearchScreenState extends ConsumerState<SearchScreen> {
   @override
   Widget build(BuildContext context) {
     final results = ref.watch(searchResultsProvider);
+    final l = AppLocalizations.of(context);
 
     return Scaffold(
       appBar: AppBar(
         title: TextField(
           controller: _controller,
           autofocus: true,
-          decoration: const InputDecoration(
+          decoration: InputDecoration(
-            hintText: 'Search notes and documents...',
+            hintText: l.searchHint,
             border: InputBorder.none,
-            hintStyle: TextStyle(color: Colors.grey),
+            hintStyle: const TextStyle(color: Colors.grey),
           ),
           onChanged: _onQueryChanged,
           onSubmitted: (value) {
@@ -72,14 +74,14 @@ class _SearchScreenState extends ConsumerState<SearchScreen> {
       ),
       body: results.when(
         loading: () => const Center(child: CircularProgressIndicator()),
-        error: (e, _) => Center(child: Text('Search error: $e')),
+        error: (e, _) => Center(child: Text(l.searchError('$e'))),
         data: (hits) {
           final query = ref.watch(searchQueryProvider);
           if (query.isEmpty) {
-            return const Center(
+            return Center(
               child: Text(
-                'Type to search your notes and documents',
+                l.typeToSearch,
-                style: TextStyle(color: Colors.grey),
+                style: const TextStyle(color: Colors.grey),
               ),
             );
           }
@@ -95,7 +97,7 @@ class _SearchScreenState extends ConsumerState<SearchScreen> {
                   ),
                   const SizedBox(height: 16),
                   Text(
-                    'No results for "$query"',
+                    l.noResultsFor(query),
                     style: Theme.of(context).textTheme.bodyLarge?.copyWith(
                       color: Theme.of(context).colorScheme.onSurfaceVariant,
                     ),
@@ -114,7 +116,7 @@ class _SearchScreenState extends ConsumerState<SearchScreen> {
                 Padding(
                   padding: const EdgeInsets.fromLTRB(16, 12, 16, 4),
                   child: Text(
-                    'Notes',
+                    l.sectionNotes,
                     style: Theme.of(context).textTheme.titleSmall?.copyWith(
                       fontWeight: FontWeight.bold,
                       color: Theme.of(context).colorScheme.primary,
@@ -129,7 +131,7 @@ class _SearchScreenState extends ConsumerState<SearchScreen> {
                 Padding(
                   padding: const EdgeInsets.fromLTRB(16, 16, 16, 4),
                   child: Text(
-                    'Documents',
+                    l.sectionDocuments,
                     style: Theme.of(context).textTheme.titleSmall?.copyWith(
                       fontWeight: FontWeight.bold,
                       color: Theme.of(context).colorScheme.primary,
@@ -209,7 +211,7 @@ class _DocumentSearchResultTile extends StatelessWidget {
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
           Text(
-            'Page ${pageNumber + 1}',
+            AppLocalizations.of(context).pageLabel(pageNumber + 1),
             style: Theme.of(context).textTheme.bodySmall,
           ),
           if (snippet.isNotEmpty)

lib/screens/settings_screen.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_colorpicker/flutter_colorpicker.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import '../l10n/app_localizations.dart';
 import '../models/pen_tool.dart';
 import '../models/pressure_curve.dart';
 import '../providers/settings_provider.dart';
@@ -20,8 +21,9 @@ class SettingsScreen extends ConsumerWidget {
     showDialog(
       context: context,
       builder: (context) {
+        final l = AppLocalizations.of(context);
         return AlertDialog(
-          title: const Text('Pick a color'),
+          title: Text(l.pickColor),
           content: SingleChildScrollView(
             child: ColorPicker(
               pickerColor: pickerColor,
@@ -31,14 +33,14 @@ class SettingsScreen extends ConsumerWidget {
           actions: [
             TextButton(
               onPressed: () => Navigator.of(context).pop(),
-              child: const Text('Cancel'),
+              child: Text(l.cancel),
             ),
             TextButton(
               onPressed: () {
                 onPicked(pickerColor);
                 Navigator.of(context).pop();
               },
-              child: const Text('OK'),
+              child: Text(l.ok),
             ),
           ],
         );
@@ -50,7 +52,7 @@ class SettingsScreen extends ConsumerWidget {
     showDialog(
       context: context,
       builder: (ctx) => AlertDialog(
-        title: const Text('Clear all local settings?'),
+        title: Text(AppLocalizations.of(ctx).clearSettingsTitle),
         content: const Text(
           'This will reset pen defaults and appearance settings. '
           'Notes and documents are not affected.',
@@ -58,17 +60,18 @@ class SettingsScreen extends ConsumerWidget {
         actions: [
           TextButton(
             onPressed: () => Navigator.pop(ctx),
-            child: const Text('Cancel'),
+            child: Text(AppLocalizations.of(ctx).cancel),
           ),
           TextButton(
             onPressed: () {
               ref.read(settingsProvider).clearAllData();
               Navigator.pop(ctx);
               ScaffoldMessenger.of(context).showSnackBar(
-                const SnackBar(content: Text('Settings reset to defaults')),
+                SnackBar(
+                    content: Text(AppLocalizations.of(context).settingsReset)),
               );
             },
-            child: const Text('Clear'),
+            child: Text(AppLocalizations.of(ctx).clear),
           ),
         ],
       ),
@@ -81,7 +84,7 @@ class SettingsScreen extends ConsumerWidget {
     final colorScheme = Theme.of(context).colorScheme;
 
     return Scaffold(
-      appBar: AppBar(title: const Text('Settings')),
+      appBar: AppBar(title: Text(AppLocalizations.of(context).settings)),
       body: ListView(
         children: [
           _SectionHeader(title: 'Defaults', icon: Icons.tune),
@@ -221,21 +224,21 @@ class SettingsScreen extends ConsumerWidget {
                 ),
                 const SizedBox(height: 4),
                 SegmentedButton<ThemeMode>(
-                  segments: const [
+                  segments: [
                     ButtonSegment(
                       value: ThemeMode.system,
-                      label: Text('System'),
+                      label: Text(AppLocalizations.of(context).themeSystem),
-                      icon: Icon(Icons.brightness_auto),
+                      icon: const Icon(Icons.brightness_auto),
                     ),
                     ButtonSegment(
                       value: ThemeMode.light,
-                      label: Text('Light'),
+                      label: Text(AppLocalizations.of(context).themeLight),
-                      icon: Icon(Icons.light_mode),
+                      icon: const Icon(Icons.light_mode),
                     ),
                     ButtonSegment(
                       value: ThemeMode.dark,
-                      label: Text('Dark'),
+                      label: Text(AppLocalizations.of(context).themeDark),
-                      icon: Icon(Icons.dark_mode),
+                      icon: const Icon(Icons.dark_mode),
                     ),
                   ],
                   selected: {settings.themeMode},
@@ -272,7 +275,7 @@ class SettingsScreen extends ConsumerWidget {
                       ),
                     ),
                     const SizedBox(width: 12),
-                    const Text('Seed color for Material 3 theme'),
+                    Text(AppLocalizations.of(context).seedColorDesc),
                   ],
                 ),
               ],

test/l10n_test.dart

@@ -18,6 +18,8 @@ class _Probe extends StatelessWidget {
         Text(l.settings),
         Text(l.toolEraser),
         Text(l.importPdf),
+        Text(l.themeSystem),
+        Text(l.searchHint),
       ]),
     );
   }
@@ -38,6 +40,8 @@ void main() {
     expect(find.text('Settings'), findsOneWidget);
     expect(find.text('Eraser'), findsOneWidget);
     expect(find.text('Import PDF'), findsOneWidget);
+    expect(find.text('System'), findsOneWidget);
+    expect(find.text('Search notes and documents...'), findsOneWidget);
   });
 
   testWidgets('Chinese locale resolves Chinese strings', (tester) async {
@@ -45,6 +49,8 @@ void main() {
     expect(find.text('设置'), findsOneWidget);
     expect(find.text('橡皮擦'), findsOneWidget);
     expect(find.text('导入 PDF'), findsOneWidget);
+    expect(find.text('跟随系统'), findsOneWidget);
+    expect(find.text('搜索笔记和文档…'), findsOneWidget);
   });
 
   test('both locales are supported', () {