Revert "Rework skill validator script (#11)"

[dacharyc]

Reverts #11

There are some changes here that don't match the behaviors I think we need to encode in our CI, so I'd like to revert the PR and discuss/modify your original PR as needed.

[Copilot]

Pull request overview

Reworks the CI skill validation approach as part of reverting prior changes from #11, moving validation logic into a GitHub Actions-focused script and updating the workflow to validate only PR-touched skills.

Changes:

• Remove the previous tools/validate-skills.sh validator script.
• Add a new .github/scripts/validate-skills.sh that detects changed skill directories via git diff and validates only those.
• Update the GitHub Actions workflow to run validation only for PRs that touch skills/**, and to invoke the new script.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
tools/validate-skills.sh	Deleted the previous “validate all skills” script.
CONTRIBUTING.md	Removed contribution/testing guidance that referenced the old script.
.github/workflows/validate-skills.yml	Updates CI to validate changed skills and adds PR path filtering + full fetch.
.github/scripts/validate-skills.sh	New CI helper script to compute changed skills and run skill-validator.

Comments suppressed due to low confidence (1)

.github/workflows/validate-skills.yml:20

• The workflow references actions/checkout@v6 and actions/setup-go@v6. As of the currently published Actions releases, these major versions don’t exist (latest known are checkout v4 and setup-go v5), so the workflow will fail to resolve the actions. Update to the latest existing major versions.

      - uses: actions/checkout@v6
        with:
          # Full history is needed so git diff can compare against the base branch
          fetch-depth: 0

      - name: Set up Go
        uses: actions/setup-go@v6
        with:
          go-version: stable

---

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[Copilot]

The failure message always prints a GitHub Actions run URL using $GITHUB_REPOSITORY and $GITHUB_RUN_ID. When this script is run outside Actions, those env vars will be unset and the URL will be malformed. Consider only printing the URL when GITHUB_ACTIONS is set (or when both variables are non-empty).

Suggested change

	echo " https://github.com/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID"
	if [ -n "${GITHUB_ACTIONS:-}" ] && [ -n "${GITHUB_REPOSITORY:-}" ] && [ -n "${GITHUB_RUN_ID:-}" ]; then
	echo " https://github.com/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID"
	fi

[Copilot]

With pull_request.paths limited to skills/**, this workflow will not run when only the validation script or workflow definition changes. That can allow CI-breaking changes to merge without being exercised. Consider including .github/workflows/validate-skills.yml and .github/scripts/validate-skills.sh in the paths filter (or removing the filter).

Suggested change

	- "skills/**"
	- "skills/**"
	- ".github/workflows/validate-skills.yml"
	- ".github/scripts/validate-skills.sh"

[Copilot]

This script uses mapfile, which is not available in the default macOS /bin/bash (3.2). Since the shebang is #!/bin/bash and the comments mention local usage (e.g., act runs), running it locally on macOS will fail. Either avoid mapfile (e.g., use a while IFS= read -r loop) or explicitly require Bash >= 4 (and consider #!/usr/bin/env bash).