fix: add missing info method to toast notifications

- Add PulseApp.ui.toast.info() method that was referenced but not implemented
- Fixes TypeError when switching update channels in settings
- Method calls showToast with 'info' type and 4000ms duration

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/public/js/ui/toastNotifications.js

@@ -229,6 +229,10 @@ PulseApp.ui.toast = (() => {
         return showToast(message, 'warning', 5000);
     }
 
+    function info(message) {
+        return showToast(message, 'info', 4000);
+    }
+
     function confirm(message, onConfirm, onCancel = null) {
         return showConfirmToast(message, onConfirm, onCancel);
     }
@@ -242,6 +246,7 @@ PulseApp.ui.toast = (() => {
         success,
         error,
         warning,
+        info,
         confirm
     };
 })();