echo "$list" | grep -q under set -o pipefail exits 141 whenever grep
matches before echo finishes writing, so healthy browsers were reported
'CDP up but no page target' and killed every 2 min fleet-wide (load 19+).
Use [[ == *glob* ]] (no pipe, no race) for the page/muse.ai stages, and
grep -c (reads to EOF, never early-exits) for the netns check.