Calends: Merge Calendars

Calends creates and maintains merged "master" calendars inside Apple Calendar. There is no account or sign-in; the app only requests Calendar access (EventKit) on first launch. TO TEST: grant calendar access, click "New master calendar," select two or more source calendars, then Build. The merged calendar appears in Apple Calendar and can be shared from there like any calendar. NEW IN 2.1: per-calendar sharing options (custom "busy" label, hide-events-by-keyword filter, optional source-calendar name in event notes), merged calendars now cover the next 18 months, and cross-device settings-sync reliability fixes. No changes to permissions, pricing, the free trial, or the in-app purchase. IN-APP PURCHASE: Calends includes a 30-day free trial, after which the one-time "Calends Lifetime" purchase unlocks the app. During the trial, a Buy bar showing the remaining days is visible at the bottom of the main window; the purchase is also available under the ⓘ info button → About Calends → Pricing. After expiry, an upgrade screen appears at launch.