v0.55.0 — super-ux

A repair for what the previous release shipped, and the gate that would have caught
it. 0.54.0 went out with its verification ledger's newest section naming v0.53.0.
This repository's own gate said nothing; the umbrella's cross-member ratchet caught it one
layer up — 3 member ledgers describe a version older than they ship, and the ratchet
stands at 2 — which is the right backstop and the wrong first line.

validate_ledger_names_its_version reads the newest ## … section, resolves the version
it names and compares it with package.json. A ledger whose newest section names an older
artifact is a release nobody re-confirmed against anything.

The first draft crashed instead of refusing. It called a fail() this module does not
have — the name belongs to a sibling repository's validator — so the plant raised
NameError and the run stopped. rc=1 either way, which is exactly why the plant looked
like it had worked. A guard that crashes has not refused anything: it stops the suite
before the rest of it can speak, and it reports a defect in itself as a defect in the
tree. Rewritten through check(), watched refusing its plant with no traceback.

Ledger section added for 0.54.0's own content, so the release it repairs is recorded
rather than skipped. repo validator checks recomputed 4621 → 4623 by running the command
docs/brand/facts.md names, not by adding two.