feat: add Telegram webhook route

Author: AidaRezaei24

src/app/api/webhooks/telegram/route.ts

@@ -0,0 +1,23 @@
+// Telegram Bot Webhook
+// Register with: POST https://api.telegram.org/bot{TOKEN}/setWebhook
+// Body: { "url": "https://YOUR_DOMAIN/api/webhooks/telegram", "secret_token": "YOUR_WEBHOOK_SECRET", "allowed_updates": ["message", "callback_query"] }
+
+import { NextRequest, NextResponse } from "next/server";
+import { handleTelegramUpdate } from "@/lib/telegram-assistant";
+
+export async function POST(req: NextRequest) {
+  const secret = req.headers.get("x-telegram-bot-api-secret-token");
+  if (secret !== process.env.TELEGRAM_WEBHOOK_SECRET) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  const update = await req.json();
+
+  try {
+    await handleTelegramUpdate(update);
+  } catch (error) {
+    console.error("Telegram webhook error:", error);
+  }
+
+  return NextResponse.json({ ok: true });
+}