v1.2.0:5 — Gear (breathing, 1-5) replaces RPE as the effort field for cardio

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.

start9/0.4/docker_entrypoint.sh

@@ -77,6 +77,11 @@ if command -v sqlite3 >/dev/null 2>&1 && [ -f "$DB_PATH" ]; then
     sqlite3 "$DB_PATH" "ALTER TABLE SetLog ADD COLUMN watts INTEGER;"
   fi
 
+  if ! sqlite3 "$DB_PATH" "PRAGMA table_info('SetLog');" 2>/dev/null | grep -q "|gear|"; then
+    log "adding missing column SetLog.gear"
+    sqlite3 "$DB_PATH" "ALTER TABLE SetLog ADD COLUMN gear INTEGER;"
+  fi
+
   if ! sqlite3 "$DB_PATH" "PRAGMA table_info('Workout');" 2>/dev/null | grep -q "|deletedAt|"; then
     log "adding missing column Workout.deletedAt"
     sqlite3 "$DB_PATH" "ALTER TABLE Workout ADD COLUMN deletedAt DATETIME;"