Add POS Pro subscription billing and free-tier limits.

Wallet-backed Pro unlocks unlimited products, restaurant mode, catalog imports, and ecosystem sync features.

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

app/Http/Middleware/EnsurePro.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use App\Services\Pos\SubscriptionService;
+use Closure;
+use Illuminate\Http\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+class EnsurePro
+{
+    public function __construct(private readonly SubscriptionService $subscriptions) {}
+
+    public function handle(Request $request, Closure $next): Response
+    {
+        $user = ladill_account() ?? $request->user();
+
+        if ($user && $this->subscriptions->isPro($user)) {
+            return $next($request);
+        }
+
+        if ($request->expectsJson()) {
+            return response()->json(['message' => 'This feature requires Ladill POS Pro.'], 402);
+        }
+
+        return redirect()->route('pos.pro.index')
+            ->with('upsell', 'That feature is part of Ladill POS Pro — subscribe to unlock it.');
+    }
+}