fix: a touch whose identity read comes back empty keeps the recorded identity and its runs (GST-1205 review)

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

bin/gstack-lease

@@ -280,6 +280,7 @@ case "$VERB" in
     }
     _tmp="$DIR/.$PID.$$"
     _id=$(identity "$PID") _keep="" _held=0 _now=$(date +%s)
+    [ -n "$_id" ] || _id=$(head -1 "$DIR/$PID" 2>/dev/null)
     if [ -f "$DIR/$PID" ] && [ "$(head -1 "$DIR/$PID" 2>/dev/null)" = "$_id" ]; then
       if [ -n "$RUN" ]; then _keep=$(fresh "$DIR/$PID" "run $RUN"); else _keep=$(fresh "$DIR/$PID" hold); fi
       [ -z "$(sed -n '2,$p' "$DIR/$PID" 2>/dev/null | grep -v '^$')" ] && _held=1