fix(backup): use message field in webhook payload, matching watchtower

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -76,7 +76,7 @@ The webhook URL is set in two places:
 - `_backup/.env` → `WEBHOOK_URL`
 - `watchtower/.env` → `NOTIFICATION_URL` (uses `generic+https://` shoutrrr scheme)
 
-Both point to the same n8n workflow at `https://n8n.pivoine.art`. The workflow accepts `{ "text": "..." }` (backup) and `{ "message": "..." }` (watchtower) and sends either field to Telegram.
+Both point to the same n8n workflow at `https://n8n.pivoine.art`. The workflow accepts `{ "message": "..." }` from both senders and forwards it to Telegram.
 
 ## Data
 

_backup/backup.sh

@@ -20,7 +20,7 @@ notify() {
   local color="$1" text="$2"
   curl -sf -o /dev/null -X POST "$WEBHOOK_URL" \
     -H 'Content-Type: application/json' \
-    -d "{\"text\":\"$text\",\"color\":\"$color\"}"
+    -d "{\"message\":\"$text\",\"color\":\"$color\"}"
 }
 
 # Truncate log on each run