feat(wrap): /wrap rules on whether a session can close, or hands it off

[pallaoro]

The end-of-session question — can I close this and delete the worktree? —
gets answered by feel, and both failure modes cost: closing on an unpushed
branch or an hour of dead ends that only lived in the context, or leaving
half-finished worktrees nobody dares delete.

/wrap forces one of two rulings: finish it now, or wrap it into something
durable and say it's safe to delete. The test is what dies when the worktree
dies, not what feels important. Four hard stops force finishing (the world
outside the repo is mid-change, the trunk is worse than you found it, what's
left is minutes of work, or you can't write the brief). Otherwise it picks
the cheapest durable form that carries the work — sidenote, committed doc,
issue, or pushed branch plus draft PR — writes a five-line brief including
the approaches already rejected, confirms the artifact landed outside the
worktree, and ends on a verdict line.

A PR needs at least one commit, so "a PR with only a description" is either
an issue or a PR whose diff is the brief committed as a doc; the ladder
routes accordingly.

Installer: the three hardcoded command copies become a COMMANDS array,
mirroring SKILLS, so the next command is a one-word edit.