feat(i18n): 添加多语言支持并重构相关组件

实现国际化(i18n)支持，包括：
1. 新增i18n配置文件和中间件
2. 重构页面和组件以支持多语言
3. 添加中英日三语翻译文件
4. 修改API路由以支持语言参数
5. 更新README文档说明i18n功能
6. 添加语言切换组件
7. 调整布局和路由结构支持多语言路径

web/package.json

@@ -30,13 +30,17 @@
     "drizzle-orm": "^0.44.4",
     "framer-motion": "^11.3.8",
     "globby": "^14.1.0",
+    "i18next": "^25.4.1",
+    "i18next-resources-to-backend": "^1.2.1",
     "lucide-react": "^0.424.0",
-    "next": "^14.2.5",
+    "next": "15.2.4",
+    "next-language-detector": "^1.1.0",
     "next-sitemap": "^4.2.3",
     "postcss": "^8.4.40",
-    "react": "^18.3.1",
-    "react-dom": "^18.3.1",
+    "react": "19.0.0",
+    "react-dom": "19.0.0",
     "react-hot-toast": "^2.4.1",
+    "react-i18next": "^15.7.2",
     "react-icons": "^5.5.0",
     "remark": "^15.0.1",
     "remark-html": "^16.0.1",