The king-of-the-hill arena's artifact: a digest-pinned, deterministic SAT solver image,
served as an attested service via Polaris. Contract: reads DIMACS at /input.cnf,
prints SAT-competition output (s ... / v ... 0), exits 10 (SAT) / 20 (UNSAT) / 0.
v0 launch champion: kissat rel-4.0.2 (Mode A — self-contained entrypoint).
Pull by digest, never :latest. Crowning a new king = a new digest in the
current-champion manifest; the image contract never changes.