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
DEVICE-COMMUNICATION.md: exhaustive reference for every phone<->watch
exchange - triggers, wire datapoints, transports (T1-T4), and the internal
structures each side mutates - plus end-to-end sequences and failure modes.
BULLETPROOFING.md: ranked gap analysis (H1-H3 session lifecycle, M1-M4
stranding/stale-UI traps, L-tier) with code evidence, failure scenarios,
fix directions, and a recommended fix order.
Claude-Session: https://claude.ai/code/session_01PVNBVKp5bcq52X722uMjwT
rzen