Suggestion to Add ShellCheck static analysis for all shell scripts

[DonRichards]

Description
The repository includes several .sh files, but there is no automated shell‑script linting. Adding ShellCheck to the workflow will catch common bugs (missed set -e, unquoted variables, etc.) before they reach production.

Proposed change

1. Add a CI step (or Makefile target) that runs ShellCheck inside the official Docker image

   # lint‑shell.sh
   docker run --rm -v "$(pwd)":/mnt koalaman/shellcheck:latest $(git ls-files '*.sh')

2. Include the script in the existing GitHub Actions workflow

   - name: ShellCheck
     run: ./lint-shell.sh

   If the project doesn’t use Actions yet, this can be a separate workflow or invoked locally via make lint-shell.

3. Fail the build on ShellCheck warnings to keep the main branch clean.

Benefits

• Detects syntax errors and unsafe patterns early.
• Enforces consistent, POSIX‑compliant shell code across contributors.

Suggestion

• CI fails when any .sh file triggers a ShellCheck warning.
• Documentation updated with make lint-shell (or equivalent) instructions.

I noticed some of my code submitted had shellcheck issues so I thought I'd add this as a suggestion. Happy to open a PR if the maintainers agree!

[pdurbin]

@DonRichards sure! Please do feel free to submit a PR! @poikilotherm set this up for us upstream and last made significant changes here, I believe: IQSS/dataverse@f8bf734