fix(css-editor): persist notification_sound + notification_volume

The CSS editor modal collected every other notification field on
save but silently dropped notification_sound and notification_volume,
so toggling them in the modal had no effect on the saved strip.
Include both in the save payload alongside the existing notification
fields.

server/src/ledgrab/static/js/features/color-strips/index.ts

@@ -180,6 +180,8 @@ class CSSEditorModal extends Modal {
             notification_default_color: getNotificationDefaultColorSnapshot(),
             notification_filter_mode: (document.getElementById('css-editor-notification-filter-mode') as HTMLInputElement).value,
             notification_filter_list: (document.getElementById('css-editor-notification-filter-list') as HTMLInputElement).value,
+            notification_sound: (document.getElementById('css-editor-notification-sound') as HTMLSelectElement).value,
+            notification_volume: getNotificationVolumeSnapshot(),
             notification_app_overrides: JSON.stringify(notificationGetRawAppOverrides()),
             clock_id: (document.getElementById('css-editor-clock') as HTMLInputElement).value,
             daylight_speed: (document.getElementById('css-editor-daylight-speed') as HTMLInputElement).value,