The /docs/skills hub page gains an embed mode for host apps that
iframe it as a skill PICKER (first consumer: Bot Mode's agent editor).
With ?embed=picker:
- docs chrome (navbar/footer/hero) is hidden
- every card gains '+ Add to this Agent', which posts
{type: 'hermes-skill-pick', name, identifier, installCmd, source}
to the parent window
The page never installs anything — the host validates event.origin
and performs the install through its own gateway (skills.manage).
Normal page rendering is untouched (no query param = no changes).