/skills install, inspect, search, browse, list now call the typed skills.manage RPC
and render results via panel/page. Previously they fell through to slash.exec which
invokes v1's curses code path — that hangs or crashes inside the Ink worker per the
§2 parity-audit finding.
Also drop Enter-as-install from the Skills Hub action stage since the Hub lists
locally installed skills; primary action is inspect-and-close. x still triggers a
manual reinstall for power users.