switch type of cronmaster to addon

frontend/public/json/cronmaster.json

@@ -5,7 +5,7 @@
     1
   ],
   "date_created": "2026-02-22",
-  "type": "pve",
+  "type": "addon",
   "updateable": true,
   "privileged": false,
   "interface_port": 3000,
@@ -31,5 +31,14 @@
     "username": null,
     "password": null
   },
-  "notes": []
+  "notes": [
+    {
+      "text": "Credentials are saved to: /root/cronmaster.creds",
+      "type": "info"
+    },
+    {
+      "text": "Update with: update_cronmaster",
+      "type": "info"
+    }
+  ]
 }