fix: backfill frontmatter so all 78 skills are discoverable by installers (50 -> 78) - #29

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Could not post PR comment (expected for fork PRs): Resource not accessible by integration - https://docs.github.com/rest/issues/comments#create-an-issue-comment

Optimize requested but TESSL_API_TOKEN not provided. Skipping optimization.