Extract inline widget closures into named StatelessWidgets (_DeviceCard,
_DeviceFilterSheet, _NotificationCard), replace magic ints and hardcoded
repeated widgets with enum-driven loops, fix the InputDecorator/DropdownButton
hack in device_actions, merge symmetric _markAsRead/_markAsNew into _setRead,
and remove dead _isLoading/_isSaving state in settings where operations are
synchronous.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
