The filter-sheet Switch now calls setCalendarHiddenSynced(), which updates local hiddenKeys immediately AND fires a sidebar_hidden PATCH to the server for caldav/google/homeassistant calendars. This makes the quick-hide consistent with the web sidebar across all devices. CalendarFilterEntry gains a source field so the sheet knows which backend to target. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>