Maintenance mode activates after current draw completes

- When admin enables maintenance, it's set to 'pending' state
- Maintenance activates automatically after the current draw completes
- Admin can use immediate=true to force immediate activation
- Frontend shows 'Maintenance Scheduled' banner when pending
- Telegram bot warns users but still allows purchases when pending
- Both mode and pending status tracked in system_settings table

telegram_bot/src/messages/index.ts

@@ -20,6 +20,17 @@ export const messages = {
     checkStatusFailed: '❌ Failed to check status',
     noPendingPurchase: '❌ No pending purchase. Please start again with /buyticket',
     setAddressFirst: '❌ Please set your Lightning Address first.',
+    maintenance: (message: string) => `🔧 *Maintenance Mode*
+
+${message}
+
+Please try again later. We'll be back soon! ⚡`,
+
+    maintenancePending: `⏳ *Maintenance Scheduled*
+
+Maintenance will begin after the current draw completes.
+
+This is your *last chance* to buy tickets for the current round! 🎟️`,
   },
 
   // ═══════════════════════════════════════════════════════════════════════════