Leg slots (stampSlotLegs — bookings boarding/alighting mid-corridor)
reaching their board/alight yard produced no ScheduleWagonAdjustmentLog
row, unlike planned couples/cuts. Without it the marshalling document
has no way to show a wagon coupling in already loaded, or uncoupling
with cargo, at a mid-corridor stop.
recordCheckpoint now logs ADD at the board yard and REMOVE at the
alight yard for these slots, deduped against existing rows since
passedYardIds re-includes earlier stops on every checkpoint call.
Purely observational — the physical wagon was already pinned to the
slot at schedule-build time, so no wagon/consist state changes.
Stage 3 of the multi-stop marshalling plan (per-event numbered docs);
stages 4-6 (generalized doc builder, endpoints, UI) still open.
9cd29a21ed