The dry-run cleanup trap replaced the lock-release trap and orphaned fallback.lock

Fallback/fallback.sh

@@ -936,8 +936,12 @@ dryrun_state_cleanup() {
     [[ "$DRY_RUN" == true && "$FALLBACK_STATE_FILE" == *".dryrun."* ]] && rm -f "$FALLBACK_STATE_FILE"
     return 0
 }
-trap 'dryrun_state_cleanup' EXIT
-trap 'FALLBACK_RUNNING=false; warn "Fallback received shutdown signal — stopping cleanly"; dryrun_state_cleanup; exit 0' \
+# Must call _release_all_locks too. acquire_lock() registers its own EXIT trap, and bash keeps
+# exactly one per signal — a bare `trap ... EXIT` here silently replaced it and orphaned
+# fallback.lock, which is the precise failure the _LOCK_FILES registry in common.sh was built to
+# stop. The signal trap only needs `exit 0`; that fires EXIT, which does both jobs.
+trap 'dryrun_state_cleanup; _release_all_locks' EXIT
+trap 'FALLBACK_RUNNING=false; warn "Fallback received shutdown signal — stopping cleanly"; exit 0' \
     SIGTERM SIGINT
 
 while [[ "$FALLBACK_RUNNING" == true ]]; do