fix(seo): make / → /en redirect permanent (301) (#188)

The root redirect was the only entry using `permanent: false` (307 temporary);
every other redirect in this file uses 301. Google treats 307 as "don't
consolidate canonicals" and kept both / and /en in the index with /en self-
canonicalizing — Search Console flagged /en as "Duplicate, Google chose
different canonical than user" (chose /).

Flipping to permanent: true emits a 308 permanent redirect, letting Google
consolidate / and /en to a single indexed URL.

Author: Mlaz-code

vercel.json

@@ -5,7 +5,7 @@
   "cleanUrls": true,
   "ignoreCommand": "git diff --quiet HEAD^ HEAD -- app/ components/ content/ pages/ public/ scripts/ styles/ theme.config.tsx next.config.mjs proxy.ts package.json vercel.json",
   "redirects": [
-    { "source": "/", "destination": "/en", "permanent": false },
+    { "source": "/", "destination": "/en", "permanent": true },
     { "source": "/streaming", "destination": "/en/streaming/overview", "permanent": true },
     { "source": "/streaming/overview", "destination": "/en/streaming/overview", "permanent": true },
     { "source": "/streaming/:path*", "destination": "/en/streaming/:path*", "permanent": true },