Cardio exercises now log a breathing "Gear" (1-5, per Brian MacKenzie)
instead of RPE (6-10) as their effort field; strength keeps RPE. An exercise
counts as cardio when its equipment type is "cardio" or it carries the
"cardio" muscle group (isCardioExercise in lib/exerciseOptions), so the
Assault Bike (type "assault bike") qualifies.
New nullable SetLog.gear column added by the boot-time guarded ALTER in
docker_entrypoint.sh (additive, idempotent); plumbed through all 5 set-write
paths, the summary/edit views, and CSV/JSON import-export. Existing rpe data
is untouched and still displays. Program/AI target-RPE is unaffected.
Keysat