Add gold credit feature gated by SuperAdmin enable_gold_credit.

Port tables, APIs, and overdue cron from goldali, default the flag off, and keep customer routes behind auth.

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

app/Console/Kernel.php

@@ -13,6 +13,11 @@ class Kernel extends ConsoleKernel
 
     protected function schedule(Schedule $schedule)
     {
+        $schedule->command('gold-credit:process-overdue')
+            ->everyFiveMinutes()
+            ->name('gold_credit_process_overdue')
+            ->withoutOverlapping();
+
         // تیک قیمت — ۶ بار در دقیقه با فاصله ۱۰ ثانیه (montzar + zaarbox + محصولات)
         // نیاز: * * * * * php artisan schedule:run
         // یا یک‌بار: php artisan schedule:bootstrap