homepage: make '/' the canonical route, 301 /home-page → /

Previous state: '/' was 307-redirected to '/home-page', and the
home-page route declared canonical='/home-page'. Net effect on
SEO: Google indexed '/home-page' as the canonical homepage and
treated '/' as a transient redirect (no link equity passed).

Changes:
- next.config.mjs: replace the source:'/' destination:'/home-page'
  temporary redirect with source:'/home-page' destination:'/'
  permanent (301). Any existing crawler entry for /home-page now
  consolidates onto '/'.
- src/app/page.tsx (new): re-exports default + metadata from
  ./home-page/page so '/' serves the homepage directly. No file
  moves required, no relative-import breakage in the home-page
  component subtree.
- src/app/home-page/page.tsx: canonical and openGraph.url
  '/home-page' → '/'. The page still builds at /home-page but
  the 301 above will redirect any hit before render.
- src/app/sitemap.ts: drop the duplicate /home-page entry — Google
  shouldn't be told about a URL that just redirects.

src/app/home-page/page.tsx

@@ -16,12 +16,12 @@ export const metadata: Metadata = {
   title: 'Broadcast Beat — Broadcast Engineering News & Insights',
   description: 'The digital platform for broadcast engineering professionals. Breaking news, deep-dive features, and industry spotlights from NAB to IBC and beyond.',
   alternates: {
-    canonical: '/home-page',
+    canonical: '/',
   },
   openGraph: {
     title: 'Broadcast Beat — Broadcast News',
     description: 'Breaking news and insights for broadcast engineering professionals.',
-    url: '/home-page',
+    url: '/',
     type: 'website',
     images: [
       {