The HKWorkoutSession could only ever be born via the phone's one-shot
startWatchApp handoff (BULLETPROOFING.md H1-H3): a dropped handoff, a
watch crash/reboot, or a run engaged manually on the wrist left the
whole workout sessionless - no heart rate, no Health save, app
suspending wrist-down - and "End Current & Start New" swallowed the
handoff against the old session's idempotency guard.
Now the coordinator self-starts a session on any reconcile that finds
an active run with none running (SessionEndPlanner.shouldStart /
runToStart, activity type from the run's split), recover() re-adopts a
crash-orphaned session at launch, and a system-ended session salvages
its Health save instead of dropping it. A .finish decided for a
session younger than 30s demotes to .discard so the stale-context
races can't save junk workouts attributed to the wrong run; parallel
completions now pick the survivor deterministically.
Claude-Session: https://claude.ai/code/session_01PVNBVKp5bcq52X722uMjwT
The HKWorkoutSession that keeps the watch app foregrounded was ended only
by ActiveWorkoutGateView's onChange(of: activeWorkouts) — a view-level side
effect. When a run ended from the phone while the watch app was
backgrounded (kept alive only by the session) or torn down and rebuilt with
an already-empty list, that onChange never fired: the session leaked (the
app kept re-foregrounding on every wrist raise) and finishAndSave() never
ran, so the HR/energy summary was neither saved to Health nor forwarded.
Move session-end off the view into a long-lived WorkoutSessionCoordinator
owned by WatchAppServices, driven by a new bridge.onWorkoutsChanged
callback fired after every authoritative cache mutation (phone push or the
watch's own optimistic edit). The decision is a pure SessionEndPlanner
seam (mirrors WatchCacheApplier): a running session ends only on a genuine
non-empty -> empty transition of the active set, so the launch race (session
running before the run doc syncs) resolves to .none and never discards a
run we haven't heard about yet. Same move as the live-mirror's
repairFromDurable, one layer down.
Watch-only; no schema or wire change. SessionEndPlannerTests pins the
decision table; the OS-initiated-end path (system ends the session itself)
stays a documented residual in PLAN-watch-session-end.md.
rzen