fix(seo): self-canonical + unique description on 6 pages that deduped to home

contact / careers / status / privacy / terms / docs set no alternates, so they
inherited the layout's canonical (= the locale homepage) — Google treats them as
duplicates of the home page and drops them. Each now sets a self-referencing
canonical + full fa/en/x-default hreflang (new shared lib/seo.ts pageAlternates)
and a unique meta description (added *Desc keys, fa/en) + per-page OpenGraph.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/website/src/app/[locale]/terms/page.tsx

@@ -1,5 +1,6 @@
 import type { Metadata } from "next";
 import { getTranslations } from "next-intl/server";
+import { SITE_URL, pageAlternates } from "@/lib/seo";
 import { Navbar } from "@/components/layout/navbar";
 import { Footer } from "@/components/layout/footer";
 import { FileText } from "lucide-react";
@@ -11,7 +12,12 @@ export async function generateMetadata({
 }): Promise<Metadata> {
   const { locale } = await params;
   const t = await getTranslations({ locale, namespace: "meta" });
-  return { title: t("termsTitle") };
+  return {
+    title: t("termsTitle"),
+    description: t("termsDesc"),
+    alternates: pageAlternates(locale, "/terms"),
+    openGraph: { title: t("termsTitle"), description: t("termsDesc"), url: `${SITE_URL}/${locale}/terms` },
+  };
 }
 
 const fa = {