Update Installed Skills

Bring the skills that the skills CLI manages up to what their source repository publishes. An update overwrites the installed folder, so it runs only after the user confirms.

What an update reaches, and what it never touches

npx skills list is the authority. Every row carries a Source: field:

• Source: owner/repo: installed by the CLI and recorded in its lock. An update replaces these.
• Source: local: written by hand, or put in a skills directory by something that is not this CLI. The CLI lists them and leaves them alone.

Symlink versus copy is not the dividing line. Symlinking is the CLI's default, so most managed skills are links: ~/.claude/skills/kw-update-skills is a symlink and the real directory behind it is ~/.agents/skills/kw-update-skills, which is where the CLI writes. npx skills add --copy opts out of the link and changes nothing about how updates work.