Types: CalendarPermission, SharedCalendarMembership, CalendarMemberInfo,
CalendarInvite, EventLockInfo. Calendar type extended with is_shared.
Hooks: useCalendars extended with shared calendar polling (5s).
useSharedCalendars for member CRUD, invite responses, color updates.
useConnections cascade invalidation on disconnect.
New components: PermissionBadge, CalendarMemberSearch,
CalendarMemberRow, CalendarMemberList, SharedCalendarSection,
SharedCalendarSettings (non-owner dialog with color, members, leave).
Modified: CalendarForm (sharing toggle, member management for owners),
CalendarSidebar (shared calendars section with localStorage visibility),
CalendarPage (shared calendar ID integration in event filtering),
NotificationToaster (calendar_invite toast with accept/decline),
NotificationsPage (calendar_invite inline actions + type icons).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
