Remove the Show/Hide Logs button and logs view from the Updates preferences
tab. Keep the logging infrastructure in SparkleUpdater for diagnostics,
but don't display it in the UI.
- Add published logMessages array to SparkleUpdater to track all update events
- Display logs in the Updates preferences tab with Show/Hide toggle
- Each log entry is timestamped and shows both info and error messages
- Logs persist during session with max 100 entries
- Users can clear logs manually
- Helps diagnose update failures directly in the app UI
