admin: redirect / to /admin (root was showing default Laravel welcome page)

admin/app/routes/web.php

@@ -2,6 +2,5 @@
 
 use Illuminate\Support\Facades\Route;
 
-Route::get('/', function () {
+// Admin root -> the Filament panel.
-    return view('welcome');
+Route::redirect("/", "/admin");
-});