Enhance ProPage: Update bot URL handling for trial subscriptions

- Introduced a new URL construction for the bot link, incorporating a 'start' parameter set to 'pro' for improved trial subscription management.
- Updated the link in the ProPage to utilize the newly constructed bot URL, ensuring users are directed correctly for Pro access through the bot.

apps/web/app/(main)/pro/page.tsx

@@ -15,6 +15,9 @@ export default async function ProPage() {
 
   const canUseTrial = !usedTrialSubscription;
 
+  const botUrl = new URL(env.BOT_URL);
+  botUrl.searchParams.set('start', 'pro');
+
   return (
     <div className="min-h-screen bg-gradient-to-br from-slate-50 via-blue-50 to-indigo-100 dark:from-slate-900 dark:via-slate-800 dark:to-slate-900">
       <PageHeader title="" />
@@ -57,7 +60,7 @@ export default async function ProPage() {
                 size="lg"
                 variant={canUseTrial ? 'outline' : 'default'}
               >
-                <Link href={env.BOT_URL} rel="noopener noreferrer" target="_blank">
+                <Link href={botUrl.toString()} rel="noopener noreferrer" target="_blank">
                   Приобрести Pro доступ через бота
                   <ArrowRight className="ml-2 size-5" />
                 </Link>