fix: 语言切换全面修复 —— 品牌层/主题首页/详情区块/404 全量 i18n（zh 矩阵 13/13）

- 站点品牌双语：每站 brandZh（品牌名/标语/hero/导航/页脚/搜索占位）由生成器写入
  站点 messages 的 zh 覆盖；SiteChrome 改为 async getTranslations 按语言渲染
- 五套主题首页接线 siteHome/hero 命名空间（新增 wire-theme-i18n.py 一次性接线脚本，
  仅处理组件函数体、hook 自动插入、hero 用 th 命名空间）
- 详情页 Use cases/Good for/FAQ/reviewCta、用例与合集索引与详情、提交页、
  对比页、Alternatives 表头与 FAQ 全部走 next-intl
- 404 双语言：locale 内走 next-intl，根级按 Accept-Language
- 修复 zh.json 中 84 处 zhXxx 旁挂键归位 + en.json 残留清理（i18n 694 键一致）
- 回归：/zh 下 13 页全中文无英文残留、无横向溢出；五站 /zh lang=zh 全部正确

sites/ai-stack/src/i18n/request.ts

@@ -6,13 +6,25 @@ import { locales, defaultLocale, type Locale } from "@aidir/core/i18n.config";
 const brandMessages = {
   en: {
     seo: { home: {"title":"AI Stack — Find the Best AI Tools, Ranked by Real Users","description":"The professional AI tools directory. 1,000+ AI tools across 14 categories ranked by community votes, reviews and engagement.","ogImage":"/og-image.png"} },
-    hero: { title: "AI Stack — Find the Best AI Tools, Ranked by Real Users", description: "The professional AI tools directory. 1,000+ AI tools across 14 categories ranked by community votes, reviews and engagement." },
+    hero: { title: "Find the best AI tools, ranked by real users", description: "1,000+ AI tools across 14 categories. Compare votes, reviews and pricing to pick the right one." },
     common: { brand: { name: "AI Stack", tagline: "The professional AI tools directory — ranked by the community." } },
+    navigation: {
+      main: { tools: "Discover", blog: "Blog" },
+      site: { items: ["Discover","Use Cases","Best Lists","Rankings","Blog","Submit"], hrefs: ["/tools","/ai-tools-for","/best","/rankings","/blog","/submit"] },
+    },
+    siteFooter: { groups: [{"title":"Discover","links":[{"label":"All Tools","href":"/tools"},{"label":"Use Cases","href":"/ai-tools-for"},{"label":"Best Lists","href":"/best"},{"label":"Rankings","href":"/rankings"}]},{"title":"Community","links":[{"label":"Submit a Tool","href":"/submit"},{"label":"Blog","href":"/blog"},{"label":"Dashboard","href":"/dashboard"}]},{"title":"Legal","links":[{"label":"Terms","href":"/terms"},{"label":"Privacy","href":"/privacy"},{"label":"Contact","href":"/contact"}]}] },
+    siteHeader: { searchPlaceholder: "Search AI tools..." },
   },
   zh: {
     seo: { home: {"title":"AI Stack — 由真实用户排名的 AI 工具目录","description":"专业 AI 工具导航：14 个分类、1000+ 工具，由社区投票、评论与互动数据实时排名。","ogImage":"/og-image.png"} },
-    hero: { title: "AI Stack — 由真实用户排名的 AI 工具目录", description: "专业 AI 工具导航：14 个分类、1000+ 工具，由社区投票、评论与互动数据实时排名。" },
-    common: { brand: { name: "AI Stack", tagline: "The professional AI tools directory — ranked by the community." } },
+    hero: { title: "找到最好的 AI 工具，由真实用户排名", description: "14 个分类、1000+ AI 工具。对比投票、评论与定价，选出最适合你的。" },
+    common: { brand: { name: "AI Stack", tagline: "由真实用户排名的专业 AI 工具目录。" } },
+    navigation: {
+      main: { tools: "发现", blog: "博客" },
+      site: { items: ["发现","用例","最佳清单","排行榜","博客","提交工具"], hrefs: ["/tools","/ai-tools-for","/best","/rankings","/blog","/submit"] },
+    },
+    siteFooter: { groups: [{"title":"发现","links":[{"label":"All Tools","href":"/tools"},{"label":"Use Cases","href":"/ai-tools-for"},{"label":"Best Lists","href":"/best"},{"label":"Rankings","href":"/rankings"}]},{"title":"社区","links":[{"label":"Submit a Tool","href":"/submit"},{"label":"Blog","href":"/blog"},{"label":"Dashboard","href":"/dashboard"}]},{"title":"法律","links":[{"label":"Terms","href":"/terms"},{"label":"Privacy","href":"/privacy"},{"label":"Contact","href":"/contact"}]}] },
+    siteHeader: { searchPlaceholder: "搜索 1000+ AI 工具..." },
   },
 } as const;