Redirect locale using the public Host header, not NextURL.origin.

A relative Location is invalid in Next.js 15 middleware; the Host header is the public site while nextUrl stays on the PM2 bind address.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/middleware.ts

@@ -16,12 +16,19 @@ export function middleware(request: NextRequest) {
   );
   if (hasLocale || PUBLIC_FILE.test(pathname)) return NextResponse.next();
 
-  // Relative Location keeps the public host; NextURL.origin is the PM2 bind address.
-  const location = `/${defaultLocale}${pathname === "/" ? "" : pathname}${request.nextUrl.search}`;
-  return new NextResponse(null, {
-    status: 307,
-    headers: { Location: location },
-  });
+  // nextUrl.origin is the PM2 bind address (localhost:3024). Use the public Host.
+  const host =
+    request.headers.get("x-forwarded-host")?.split(",")[0]?.trim() ||
+    request.headers.get("host");
+  const proto =
+    request.headers.get("x-forwarded-proto")?.split(",")[0]?.trim() || "https";
+  const origin = host ? `${proto}://${host}` : request.nextUrl.origin;
+  const dest = new URL(
+    `/${defaultLocale}${pathname === "/" ? "" : pathname}`,
+    origin,
+  );
+  dest.search = request.nextUrl.search;
+  return NextResponse.redirect(dest);
 }
 
 export const config = {