Sidebar-column toolbar items are confined to the sidebar's narrow
section of the unified toolbar and collapse into overflow; attaching
New Routine and Starter Gallery to the split view gives them the full
trailing section.
A new 'Workouts Mac' target (same bundle ID as iOS, universal purchase)
with a NavigationSplitView shell over the shared data/sync layers:
routine management with starter gallery and seed-fork follow, schedule
editing (reminders stay iPhone-scheduled), and a browse-only exercise
library with the animated figures and reference guides.
Multi-writer stance: the Mac writes only routine and schedule documents
(whole-document last-writer-wins) and never workout documents, whose
per-log merge exists only on the watch ingest path. The Mac reconciles
on window activation (throttled) since iCloud syncs while the app is
closed, and flushes pending writes on deactivation.
rzen