refactor: 迁移 i18n 系统从 react-i18next 到 chrome.i18n

- 移除 react-i18next、i18next 及相关依赖
- 删除旧的 i18n/ 目录和 useLazyTranslation 工具
- 新增 utils/chromeI18n.ts 类型安全 wrapper（useI18n Hook + getMessage）
- 生成 public/_locales/{zh,en}/messages.json（298 个翻译 key）
- 批量更新 39+ 组件文件的导入和翻译调用
- 转换翻译键格式：namespace:key → namespace_key
- 修复 ErrorBoundary/PageErrorBoundary 从 withTranslation HOC 改为直接调用 getMessage
- 更新 vitest.setup.ts mock 加载实际翻译文本
- 修复 11 个测试文件的断言以匹配中文翻译
- TypeScript、ESLint、547 项测试全部通过

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

pages/JsonTools/DiffNavigator.tsx

@@ -1,6 +1,6 @@
 import React from 'react';
 import { ChevronLeft, ChevronRight } from 'lucide-react';
-import { useLazyTranslation } from '@/utils/useLazyTranslation';
+import { useI18n } from '@/utils/chromeI18n';
 import { cn } from '@/lib/utils'; // 1. 引入标准的 shadcn 工具函数
 
 export interface DiffNavigatorProps extends React.HTMLAttributes<HTMLDivElement> {
@@ -19,7 +19,7 @@ export default function DiffNavigator({
   className,
   ...props
 }: DiffNavigatorProps) {
-  const { t } = useLazyTranslation('jsonDiff');
+  const { t } = useI18n('jsonDiff');
 
   // 计算当前的边界禁用状态守卫
   const isFirst = currentIndex <= 0;

pages/JsonTools/DiffResult.tsx

@@ -1,5 +1,5 @@
 import React from 'react';
-import { useLazyTranslation } from '@/utils/useLazyTranslation';
+import { useI18n } from '@/utils/chromeI18n';
 import { cn } from '@/lib/utils';
 import JsonTree from './JsonTree';
 import type { DiffNode, DiffResult as DiffResultType, DiffType, ViewMode } from './types';
@@ -18,7 +18,7 @@ export default function DiffResult({
   className,
   ...props
 }: DiffResultProps) {
-  const { t } = useLazyTranslation('jsonDiff');
+  const { t } = useI18n('jsonDiff');
 
   if (viewMode === 'sideBySide') {
     return (

pages/JsonTools/JsonConvertSection.tsx

@@ -1,5 +1,5 @@
 import React, { useEffect, useMemo, useState } from 'react';
-import { useLazyTranslation } from '@/utils/useLazyTranslation';
+import { useI18n } from '@/utils/chromeI18n';
 import { formatByteSize } from '@/utils/textStatistics';
 import CopyButton from '@/components/CopyButton';
 import TextInputArea from '@/components/TextInputArea';
@@ -25,7 +25,7 @@ export default function JsonConvertSection({
   className,
   ...props
 }: JsonConvertSectionProps) {
-  const { t } = useLazyTranslation('jsonFormat');
+  const { t } = useI18n('jsonFormat');
 
   const [input, setInput] = useState('');
   const [debouncedInput, setDebouncedInput] = useState('');

pages/JsonTools/JsonFormatSection.tsx

@@ -1,5 +1,5 @@
 import { useEffect, useMemo, useState } from 'react';
-import { useLazyTranslation } from '@/utils/useLazyTranslation';
+import { useI18n } from '@/utils/chromeI18n';
 import {
   formatJson,
   type JsonFormatOptions,
@@ -14,7 +14,7 @@ import { Checkbox } from '@/components/ui/checkbox';
 import { Label } from '@/components/ui/label';
 
 export default function JsonFormatSection() {
-  const { t } = useLazyTranslation('jsonFormat');
+  const { t } = useI18n('jsonFormat');
 
   const [input, setInput] = useState('');
   const [debouncedInput, setDebouncedInput] = useState('');

pages/JsonTools/index.tsx

@@ -1,5 +1,5 @@
 import { useCallback, useEffect, useMemo, useState } from 'react';
-import { useLazyTranslation } from '@/utils/useLazyTranslation';
+import { useI18n } from '@/utils/chromeI18n';
 import JsonDiffInput from './JsonDiffInput';
 import DiffResult from './DiffResult';
 import DiffNavigator from './DiffNavigator';
@@ -37,7 +37,7 @@ const isValidPageMode = (val: unknown): val is JsonToolsPageMode =>
 type PageMode = JsonToolsPageMode;
 
 export default function Index() {
-  const { t } = useLazyTranslation(['jsonDiff', 'jsonFormat']);
+  const { t } = useI18n(['jsonDiff', 'jsonFormat']);
   const [pageMode, setPageMode] = useStorageState('jsonTools/pageMode', 'diff', isValidPageMode);
 
   // 1. 受控原始输入源