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/launchai/src/app/[locale]/not-found.tsx

@@ -0,0 +1,2 @@
+// 自动生成：[locale]/not-found.tsx 的薄路由
+export { default } from "@aidir/core/pages/[locale]/not-found";

sites/launchai/src/i18n/request.ts

@@ -6,13 +6,25 @@ import { locales, defaultLocale, type Locale } from "@aidir/core/i18n.config";
 const brandMessages = {
   en: {
     seo: { home: {"title":"LaunchAI — Discover and Upvote Today's AI Products","description":"A daily launch feed for AI products. Upvote the best AI tools, follow makers and climb the leaderboard.","ogImage":"/og-image.png"} },
-    hero: { title: "LaunchAI — Discover and Upvote Today's AI Products", description: "A daily launch feed for AI products. Upvote the best AI tools, follow makers and climb the leaderboard." },
+    hero: { title: "Today's AI product launches", description: "Fresh AI products, every day. Upvote the best ones to the top." },
     common: { brand: { name: "LaunchAI", tagline: "Discover and upvote today's AI products." } },
+    navigation: {
+      main: { tools: "Today", blog: "Blog" },
+      site: { items: ["Today","Leaderboard","Categories","Collections","Blog","Submit"], hrefs: ["/","/rankings","/tools","/best","/blog","/submit"] },
+    },
+    siteFooter: { groups: [{"title":"Community","links":[{"label":"Submit a Product","href":"/submit"},{"label":"Leaderboard","href":"/rankings"},{"label":"Dashboard","href":"/dashboard"}]},{"title":"Explore","links":[{"label":"All Products","href":"/tools"},{"label":"Use Cases","href":"/ai-tools-for"},{"label":"Collections","href":"/best"}]},{"title":"About","links":[{"label":"Blog","href":"/blog"},{"label":"Terms","href":"/terms"},{"label":"Privacy","href":"/privacy"}]}] },
+    siteHeader: { searchPlaceholder: "Search AI products..." },
   },
   zh: {
     seo: { home: {"title":"LaunchAI — 发现并投票今日 AI 新品","description":"AI 产品每日发布社区：为最好的 AI 工具投票，登上社区排行榜。","ogImage":"/og-image.png"} },
-    hero: { title: "LaunchAI — 发现并投票今日 AI 新品", description: "AI 产品每日发布社区：为最好的 AI 工具投票，登上社区排行榜。" },
-    common: { brand: { name: "LaunchAI", tagline: "Discover and upvote today's AI products." } },
+    hero: { title: "今日 AI 产品发布", description: "每天上新。为最好的产品投票，冲上排行榜。" },
+    common: { brand: { name: "LaunchAI", tagline: "发现并投票今日的 AI 新品。" } },
+    navigation: {
+      main: { tools: "今日", blog: "博客" },
+      site: { items: ["今日","排行榜","分类","合集","博客","提交产品"], hrefs: ["/","/rankings","/tools","/best","/blog","/submit"] },
+    },
+    siteFooter: { groups: [{"title":"社区","links":[{"label":"Submit a Product","href":"/submit"},{"label":"Leaderboard","href":"/rankings"},{"label":"Dashboard","href":"/dashboard"}]},{"title":"探索","links":[{"label":"All Products","href":"/tools"},{"label":"Use Cases","href":"/ai-tools-for"},{"label":"Collections","href":"/best"}]},{"title":"关于","links":[{"label":"Blog","href":"/blog"},{"label":"Terms","href":"/terms"},{"label":"Privacy","href":"/privacy"}]}] },
+    siteHeader: { searchPlaceholder: "搜索 AI 产品..." },
   },
 } as const;
 

sites/launchai/src/site/brand.tsx

@@ -2,6 +2,26 @@ import type { SiteConfig } from "@/kit/types";
 
 // LaunchAI —— 独立站点的全部品牌/导航/页脚配置
 export const siteConfig: SiteConfig = {
+  "brandZh": {
+    "name": "LaunchAI",
+    "tagline": "发现并投票今日的 AI 新品。",
+    "headline": "今日 AI 产品发布",
+    "subheadline": "每天上新。为最好的产品投票，冲上排行榜。",
+    "nav": [
+      "今日",
+      "排行榜",
+      "分类",
+      "合集",
+      "博客",
+      "提交产品"
+    ],
+    "footer": [
+      "社区",
+      "探索",
+      "关于"
+    ],
+    "searchPlaceholder": "搜索 AI 产品..."
+  },
   "accent": "16 85% 55%",
   "port": 3002,
   "brand": {

sites/launchai/src/site/home.tsx

@@ -1,6 +1,7 @@
 // 自动生成：站点首页组件（源自底座 product 形态，品牌来自 @/site/brand）
 import { siteConfig } from "@/site/brand";
 import { Flame, Trophy, Rocket, ChevronRight, MessageSquare } from "lucide-react";
+import { getTranslations } from "next-intl/server";
 import { VoteButton } from "@/features/voting/components/vote-button";
 import { LocaleLink } from "@/components/locale-link";
 import { ToolLogo } from "@/components/tool-logo";
@@ -103,6 +104,8 @@ function LaunchRow({
 }
 
 async function SiteHome({ locale }: { locale: string }) {
+  const t = await getTranslations("siteHome");
+  const th = await getTranslations("hero");
   const data = await getHomeDataSafe(10);
 
   return (
@@ -111,17 +114,17 @@ async function SiteHome({ locale }: { locale: string }) {
       <section className="border-b border-border bg-gradient-to-b from-primary/5 to-background">
         <div className="mx-auto max-w-5xl px-4 py-12 text-center sm:px-6 md:py-16">
           <h1 className="text-2xl font-extrabold tracking-tight text-foreground sm:text-4xl">
-            {siteConfig.brand.headline}
+            {th("title")}
           </h1>
           <p className="mt-3 text-sm text-muted-foreground sm:text-base">
-            {siteConfig.brand.subheadline}
+            {th("description")}
           </p>
           <LocaleLink
             href="/submit"
             className="mt-6 inline-flex items-center gap-1.5 rounded-full bg-primary px-6 py-2.5 text-sm font-semibold text-primary-foreground shadow transition-all hover:opacity-90"
           >
             <Rocket className="h-4 w-4" />
-            Launch your product
+            {t("launchButton")}
           </LocaleLink>
         </div>
       </section>
@@ -140,14 +143,14 @@ async function SiteHome({ locale }: { locale: string }) {
               ))
             ) : (
               <p className="px-6 py-12 text-center text-sm text-muted-foreground">
-                No launches yet — be the first to submit.
+                {t("noLaunches")}
               </p>
             )}
             <LocaleLink
               href="/tools"
               className="flex items-center justify-center gap-1 border-t border-border py-3 text-xs font-medium text-muted-foreground hover:text-primary"
             >
-              Browse all products
+              {t("feedBrowse")}
               <ChevronRight className="h-3 w-3" />
             </LocaleLink>
           </div>
@@ -155,7 +158,7 @@ async function SiteHome({ locale }: { locale: string }) {
           {/* New */}
           {data.newest.length > 0 && (
             <div className="mt-8">
-              <SectionHeader title="Fresh launches" viewAllHref="/rankings?board=new" />
+              <SectionHeader title={t("newTitle")} viewAllHref="/rankings?board=new" />
               <div className="overflow-hidden rounded-2xl border border-border bg-background">
                 {data.newest.slice(0, 5).map((tool) => (
                   <LaunchRow key={tool.id} tool={tool} locale={locale} />
@@ -200,14 +203,14 @@ async function SiteHome({ locale }: { locale: string }) {
                 href="/rankings"
                 className="mt-4 block rounded-lg border border-border py-2 text-center text-xs font-medium text-muted-foreground hover:border-primary/40 hover:text-primary"
               >
-                Full leaderboard
+                {t("leaderboardFull")}
               </LocaleLink>
             </div>
           )}
 
           {data.editorsChoice.length > 0 && (
             <div className="rounded-2xl border border-border bg-background p-5">
-              <h3 className="text-sm font-bold text-foreground">Editor's picks</h3>
+              <h3 className="text-sm font-bold text-foreground">{t("picksEditorialLabel")}</h3>
               <ol className="mt-4 space-y-3">
                 {data.editorsChoice.slice(0, 4).map((tool) => (
                   <li key={tool.id}>