fix: update environment variables in Dockerfile and use config for host in sitemap generation

src/app/api/sitemapBuilder/route.ts

@@ -3,8 +3,7 @@
 // app/(api)/sitemap/route.ts
 import { NextResponse } from 'next/server';
 import { productCategoriesData } from '../product_categories/data';
-
-const HOST = 'http://localhost:3000';
+import { host } from '@/config';
 
 const pages = [
   '/',
@@ -30,7 +29,7 @@ export async function GET() {
         const loc = `/${locale}`;
         return `
           <url>
-            <loc>${HOST}${loc}${page}</loc>
+            <loc>${host}${loc}${page}</loc>
             <changefreq>weekly</changefreq>
             <priority>0.8</priority>
           </url>