feat(landing): add i18n + language switcher to TopNav (#163)

Nav links and CTA buttons were hardcoded Chinese strings in MarketingShell.
Switch them to Paraglide messages so they follow the active locale, and add
LanguageSwitcher to TopNav so users can toggle language from the landing page.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: dengzhaofun

apps/admin/messages/en.json

@@ -3245,5 +3245,13 @@
   "aria_more_actions": "More actions",
   "aria_loading_chart": "Loading chart",
   "members_more_actions": "More actions",
-  "invitations_more_actions": "More actions"
+  "invitations_more_actions": "More actions",
+  "nav_platform": "Platform",
+  "nav_modules": "Modules",
+  "nav_workflow": "Workflow",
+  "nav_developer": "Developer",
+  "nav_pricing": "Pricing",
+  "nav_docs": "Docs",
+  "auth_sign_in": "Sign in",
+  "auth_sign_up_cta": "Get started"
 }

apps/admin/messages/zh.json

@@ -3245,5 +3245,13 @@
   "aria_more_actions": "更多操作",
   "aria_loading_chart": "图表加载中",
   "members_more_actions": "更多操作",
-  "invitations_more_actions": "更多操作"
+  "invitations_more_actions": "更多操作",
+  "nav_platform": "平台",
+  "nav_modules": "模块",
+  "nav_workflow": "工作流",
+  "nav_developer": "开发者",
+  "nav_pricing": "定价",
+  "nav_docs": "文档",
+  "auth_sign_in": "登录",
+  "auth_sign_up_cta": "免费开始"
 }

apps/admin/src/components/landing/MarketingShell.tsx

@@ -2,8 +2,10 @@ import { Link } from "@tanstack/react-router";
 import { ArrowRight, Github } from "lucide-react"
 
 import { ConsentSettingsButton } from "#/components/consent/ConsentLayer"
+import { LanguageSwitcher } from "#/components/LanguageSwitcher"
 import ThemeToggle from "#/components/ThemeToggle"
 import { Button } from "#/components/ui/button"
+import * as m from "#/paraglide/messages.js"
 import { getLocale } from "#/paraglide/runtime.js"
 
 const t = (zh: string, en: string) => (getLocale() === "zh" ? zh : en)
@@ -35,14 +37,16 @@ export function SectionTitle({ children }: { children: React.ReactNode }) {
 /*  Nav + Footer                                                              */
 /* -------------------------------------------------------------------------- */
 
-const NAV_LINKS: Array<{ label: string; href: string; type: "anchor" | "route" }> = [
-  { label: "平台", href: "/#platform", type: "anchor" },
-  { label: "模块", href: "/#modules", type: "anchor" },
-  { label: "工作流", href: "/#workflow", type: "anchor" },
-  { label: "开发者", href: "/#developer", type: "anchor" },
-  { label: "定价", href: "/pricing", type: "route" },
-  { label: "文档", href: "/docs", type: "route" },
-]
+function getNavLinks() {
+  return [
+    { label: m.nav_platform(), href: "/#platform", type: "anchor" as const },
+    { label: m.nav_modules(), href: "/#modules", type: "anchor" as const },
+    { label: m.nav_workflow(), href: "/#workflow", type: "anchor" as const },
+    { label: m.nav_developer(), href: "/#developer", type: "anchor" as const },
+    { label: m.nav_pricing(), href: "/pricing", type: "route" as const },
+    { label: m.nav_docs(), href: "/docs", type: "route" as const },
+  ]
+}
 
 function TopNav() {
   return (
@@ -55,18 +59,19 @@ function TopNav() {
           <span>ApolloKit</span>
         </Link>
         <nav className="hidden items-center gap-6 text-sm text-muted-foreground md:flex">
-          {NAV_LINKS.map((l) => (
+          {getNavLinks().map((l) => (
             <a key={l.href} href={l.href} className="hover:text-foreground">
               {l.label}
             </a>
           ))}
         </nav>
         <div className="ml-auto flex items-center gap-2">
+          <LanguageSwitcher />
           <ThemeToggle />
           <Button
             render={
               <Link to="/auth/$authView" params={{ authView: "sign-in" }}>
-                登录
+                {m.auth_sign_in()}
               </Link>
             }
             variant="ghost"
@@ -76,7 +81,7 @@ function TopNav() {
           <Button
             render={
               <Link to="/auth/$authView" params={{ authView: "sign-up" }}>
-                免费开始
+                {m.auth_sign_up_cta()}
                 <ArrowRight className="ml-1 size-3.5" />
               </Link>
             }