chore: per-skill releases

[Rodriguespn]

Summary

Switches the release model from a single monorepo release to a multi-package setup where each skill is versioned independently, while keeping a single root release.

Each skill package gets its own release-please entry. When a skill's files change, Release Please opens a release PR that bumps only that skill's metadata.version in SKILL.md and generates a per-skill CHANGELOG.md. We setup skip-github-release: true so no GitHub release is created for skill packages.

The unchanged skills are never bumped.

A single GitHub release is created at the root level.

Closes AI-780

[gregnr]

@Rodriguespn dug into this a bit and I have a proposal - skip the per-skill releases, and keep just the single bundled root-level release. This eliminates the draft + force tag song and dance, since ultimately we don't really need GitHub releases per-skill anyway. What we care about is separate versions per skill.

I did a bit of research and it looks like this setup should be possible with release-please:

1. Keep the manifest mode with per-skill versions + root version
2. In release-please-config.json
   a. Set skip-github-release: true for each of the skills (but not root)
   b. Set per-skill changelog.md paths, e.g. skills/{name}/CHANGELOG.md
   c. Turn off changelog.md for root, skip-changelog: true

In the end we get nice per-changelog files committed with each skill, but only a single central release for the bundle.

[Rodriguespn]

@Rodriguespn dug into this a bit and I have a proposal - skip the per-skill releases, and keep just the single bundled root-level release. This eliminates the draft + force tag song and dance, since ultimately we don't really need GitHub releases per-skill anyway. What we care about is separate versions per skill.

I did a bit of research and it looks like this setup should be possible with release-please:

1. Keep the manifest mode with per-skill versions + root version
2. In release-please-config.json
   a. Set skip-github-release: true for each of the skills (but not root)
   b. Set per-skill changelog.md paths, e.g. skills/{name}/CHANGELOG.md
   c. Turn off changelog.md for root, skip-changelog: true

In the end we get nice per-changelog files committed with each skill, but only a single central release for the bundle.

That works even better, thanks for the suggestion @gregnr 💯
Any reason to skip the root level changelog? I understand that the info is already in the per skill changelog but since we have one single release, I find it useful to have a main changelog where we can check the changes between releases without having to navigate the each skill changelog. What are your thoughts on this?

[gregnr]

Latest changes LGTM

Any reason to skip the root level changelog?

Since CHANGELOG.md is committed to the repo, to me it's cleaner to keep these isolated to each skill vs. duplicate the combined content again at the root. There will still be the root-level bundled changes on the GitHub release itself.