Update to Unix Copilot

{
  "description": "Author maintainable Bash, zsh or POSIX shell scripts with input checks, cleanup, safe paths and tests.",
  "included_files": [],
  "name": "write-shell-script",
  "skill_md_contents": "---\nname: write-shell-script\ndescription: Author maintainable Bash, zsh or POSIX shell scripts with input checks, cleanup, safe paths and tests.\n---\n\n# Write a shell script\n\n## Scope and execution truth\nThis is a skills-only assistant workflow. Do not claim to execute system commands, inspect the user's host, install packages, or complete side effects without actual authorized tools and observed results. User-pasted output is evidence, not a machine connection.\n\n## Procedure\n1. Decide shell/interpreter and portability requirement first. Use an explicit shebang and check declared dependencies.\n2. Define arguments, input/output contracts, expected errors and idempotency before adding code.\n3. Quote expansions; use `\"$@\"` or arrays where supported; protect leading-dash filenames and handle weird filenames where relevant.\n4. Handle nonzero exit statuses explicitly for critical steps. `set -e` and `pipefail` are not magic guarantees; document shell-specific support.\n5. Use secure temporary files, `trap` cleanup when needed, and stage → validate → publish for important outputs.\n6. Add dry-run or preview mode for write operations when practical, plus simple representative tests and usage examples.\n\n## Relevant references\n- Read `../../references/shell-debugging.md` for domain-specific guidance.\n- Read `../../references/shell-quoting.md` for domain-specific guidance.\n- Read `../../references/automation-and-recovery.md` for domain-specific guidance.\n\n## Completion checks\n- Shell-specific features match shebang\n- Failure and cleanup cases addressed\n- Repeat-run behavior considered\n\n## Deliverable\nUse the minimum format that makes the answer actionable: the actual command or patch, platform assumptions, a preview before risky changes, and a reproducible validation step. Clearly label proposed actions versus observed execution.\n"
}