fix(website): revert generateStaticParams params to non-Promise

generateStaticParams receives plain params (not Promise).
Only page/layout default exports get Promise params in Next.js 15+.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/website/src/app/[locale]/blog/[slug]/page.tsx

@@ -10,13 +10,12 @@ import { JsonLd } from "@/components/seo/json-ld";
 import { getPostBySlug, getAllPosts } from "@/lib/blog";
 import { ArrowLeft, ArrowRight, Clock, Calendar } from "lucide-react";
 
-export async function generateStaticParams({
+export function generateStaticParams({
   params,
 }: {
-  params: Promise<{ locale: string }>;
+  params: { locale: string };
 }) {
-  const { locale } = await params;
-  const posts = getAllPosts(locale as "fa" | "en");
+  const posts = getAllPosts(params.locale as "fa" | "en");
   return posts.map((p) => ({ slug: p.slug }));
 }