feat: mail telegram and cron check

lib/telegram.ts

@@ -0,0 +1,10 @@
+export async function sendTelegram(chatId: string, text: string): Promise<void> {
+  const token = process.env.TELEGRAM_BOT_TOKEN;
+  if (!token) throw new Error("TELEGRAM_BOT_TOKEN fehlt");
+  const res = await fetch(`https://api.telegram.org/bot${token}/sendMessage`, {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify({ chat_id: chatId, text }),
+  });
+  if (!res.ok) throw new Error(`Telegram ${res.status}`);
+}