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>

vitest.setup.ts

@@ -1,66 +1,45 @@
 import '@testing-library/jest-dom';
 import { afterEach, beforeEach, vi } from 'vitest';
-import { readFileSync } from 'fs';
-import { resolve } from 'path';
 import React from 'react';
 
-// 读取中文翻译文件用于 withTranslation mock
-const zhCommon = JSON.parse(
-  readFileSync(resolve(__dirname, 'i18n/locales/zh/common.json'), 'utf-8'),
-);
+// Load actual zh translations for getMessage mock
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+const zhMessages: Record<
+  string,
+  { message: string }
+> = require('./public/_locales/zh/messages.json');
 
-// 支持嵌套 key 查找，如 "errorBoundary.title" → zhCommon.errorBoundary.title
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
-function nestedLookup(obj: Record<string, any>, key: string): string | undefined {
-  const parts = key.split('.');
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  let current: any = obj;
-  for (const part of parts) {
-    if (current == null || typeof current !== 'object') return undefined;
-    current = current[part];
-  }
-  return typeof current === 'string' ? current : undefined;
-}
-
-vi.mock('@/utils/useLazyTranslation', () => ({
-  useLazyTranslation: (ns?: string) => ({
-    // 自动承接命名空间前缀过滤，100% 模拟真实多语种直出
-    t: (key: string) => (ns ? `${ns}:${key}` : key),
+vi.mock('@/utils/chromeI18n', () => ({
+  useI18n: (ns?: string | string[]) => ({
+    t: (key: string) => {
+      let msgId = key;
+      // Handle namespace:key format
+      if (key.includes(':')) {
+        msgId = key.replace(':', '_').replace(/\./g, '_');
+      }
+      // Try direct key first
+      if (zhMessages[msgId]) return zhMessages[msgId].message;
+      // Try namespace prefix (using converted msgId)
+      if (ns) {
+        const namespaces = Array.isArray(ns) ? ns : [ns];
+        for (const n of namespaces) {
+          const candidate = `${n}_${msgId}`;
+          if (zhMessages[candidate]) return zhMessages[candidate].message;
+        }
+      }
+      return msgId;
+    },
     i18n: {
       changeLanguage: vi.fn().mockResolvedValue(undefined),
-      language: 'zh-CN',
+      language: 'zh',
     },
     isLoaded: true,
   }),
-}));
-
-vi.mock('react-i18next', () => ({
-  useTranslation: () => ({
-    t: (key: string) => key,
-    i18n: {
-      changeLanguage: vi.fn().mockResolvedValue(undefined),
-      language: 'zh-CN',
-    },
-  }),
-  withTranslation: (ns?: string) => {
-    const translations = ns === 'common' ? zhCommon : {};
-    // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    return (Component: React.ComponentType<any>) => {
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      const Wrapped = (props: any) =>
-        React.createElement(Component, {
-          ...props,
-          t: (key: string) => nestedLookup(translations, key) || key,
-          i18n: { language: 'zh-CN', changeLanguage: vi.fn() },
-        });
-      Wrapped.displayName = `withTranslation(${Component.displayName || Component.name || 'Component'})`;
-      return Wrapped;
-    };
-  },
-  initReactI18next: {
-    type: '3rdParty',
-    init: vi.fn().mockResolvedValue(undefined),
-  },
+  getMessage: (msgId: string) => zhMessages[msgId]?.message ?? msgId,
+  getLanguage: () => 'zh',
+  normalizeLanguage: (lng: string) => (lng.startsWith('zh') ? 'zh' : 'en'),
+  SUPPORTED_LANGUAGES: ['zh', 'en'],
+  preloadNamespaces: vi.fn().mockResolvedValue(undefined),
 }));
 
 vi.mock('@/components/CopyButton', () => ({