Extract CalendarPickerGroups into ui/common: the calendar-manager screen's
grouped-card system (device chip for local calendars, the owning app's
launcher icon per synced account, colour chip + check per calendar) as a
single reusable picker. Use it in both the event editor and the .ics import
screen so all 'which calendar' lists match.
Moves LeadingAvatar/SourceLogo/curatedSourcePackage out of CalendarsScreen
into common as the shared source of truth. Drops the redundant 'Add to
calendar' caption from the import picker.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Jean-Luc Makiola
4a11c951ae