Move the text-measurement cache, shared column-width state, 5-second settle timer, and persisted device-column width into a dedicated SensorColumnMeasurer service. MainWindow keeps the traced UpdateSensorColumnWidths wrapper and subscribes to a SettleTriggered event so tracing semantics are preserved.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
