> They are more than that, for example the frontmatter and code files around them.

You are right. I have edited my post slightly.

> Why do I want to throw away my dependency management system and shared libraries folder for putting scripts in skills?

You don't have to put scripts in skills. The script can be anywhere the agent can access. The skill just needs to tell the LLM how to run it.

> Does it even make sense to have skills in the repo? How do I use them across projects?

You don't have to put them in the repo. E.g. with Claude Code you can put project-specific skills in `.claude/skills` in the repo and system-wide skills in `~/.claude/skills`.