9e744d701f
lint.yml has shellchecked every workflow `run:` step since the dash-vs-bash incidents, but nothing had ever pointed shellcheck at entrypoint.sh, scripts/*.sh or the extensionless tools under rootfs/usr/local/bin/. That gap is not hypothetical: the skillset repo's ci-release-watcher template shipped `echo "$json" | python3 <<'EOF' ... json.load(sys.stdin)` for two months, where the heredoc IS python's stdin (no script arg) so the load hit EOF and the function silently returned nothing. shellcheck names exactly that at severity ERROR — SC2259, "This redirection overrides piped input" — and could have named it the whole time. New step in the existing actionlint job, so no second container pull: shellcheck -S error plus bash -n over every shell file, discovered as *.sh UNION a shebang scan (the glob alone misses pi-devbox-version, devbox-skill-reconcile, dot-watch and studio-expose; a shebang scan alone would miss a sourced fragment without one). Fails loudly on a zero-file match, because a green tick over an empty set is not a check. Severity chosen by measurement, not taste: -S error is 0 findings across all 11 shell files today, so the gate is green on arrival with no cleanup, while -S warning is NOT free (19x SC2088 tilde-in-quotes in recreate-sanity-check.sh plus assorted SC2016, all intentional) and would train everyone to ignore the job — the same reasoning as the SHELLCHECK_OPTS exclusions already on the actionlint step.