Serve the site in English, Spanish and Arabic, add a captcha, make the message optional

- Move every route under app/[lang]; a proxy keeps English on unprefixed URLs and serves /es and /ar
- Interface strings and homepage copy per locale; content pages load a translated JSON when one exists
- Language switch in the header, hreflang alternates and a multilingual sitemap
- Right-to-left layout for Arabic with logical CSS properties, Noto Sans Arabic and no letter-spacing
- Self-hosted proof-of-work "I'm not a robot" check (no third-party account) replaces Turnstile
- The message field is optional; failed attempts refill the form instead of clearing it

src/lib/metadata.ts

@@ -1,13 +1,32 @@
 import type { Metadata } from "next";
+import { locales, localize, ogLocale, type Locale } from "@/i18n/config";
 import type { Page } from "./pages";
 
+/** Canonical URL plus hreflang alternates for a locale-free path. */
+export function localeAlternates(path: string, locale: Locale): Metadata["alternates"] {
+  return {
+    canonical: localize(path, locale),
+    languages: {
+      ...Object.fromEntries(locales.map((l) => [l, localize(path, l)])),
+      "x-default": path,
+    },
+  };
+}
+
 export function pageMetadata(page: Page): Metadata {
   const title = page.meta.title ?? "AI Growth Technologies";
   const description = page.meta.description ?? undefined;
   return {
     title,
     description,
-    alternates: { canonical: page.path },
-    openGraph: { type: "website", url: page.path, siteName: "AI Growth Technologies", title, description },
+    alternates: localeAlternates(page.path, page.locale),
+    openGraph: {
+      type: "website",
+      url: localize(page.path, page.locale),
+      siteName: "AI Growth Technologies",
+      locale: ogLocale[page.locale],
+      title,
+      description,
+    },
   };
 }