0.31.0

Inputs kept as written, and a certificate tied to its obligation. No new
commands (59) and no new kinds (61); the schema stays 5. New optional fields:
cleared (ideal) and scope (cegis, cegis_none).

Fixed

• A binary variable kept its bounds only above. variable("x", 1, 1, kind="binary") came back as (0, 1), and opt certified the minimum of a
  program where x could be 0. The bounds are now intersected with {0, 1}; an
  empty range is refused.
• Hypergraph and cover labels that print alike were merged. [1, 2] and
  ["1", "2"] became one hyperedge (a matching of 2 reported as 1), and a
  JSON spec read "1" as a number. Labels stay as written, and two different
  elements with the same printed identity are refused before any verdict.
• A hypergraph with no hyperedges (a triangle-free graph) is nu = tau = 0
  with its certificate, not an error.
• The API ran a HypergraphSpec as its LP under every command, so
  api.run("cover", h, maximum=True) was refused; it is now read by the
  command, and cover takes minimum, maximum and sat in the API too.
• verify --spec with the right hash at another path no longer warns that
  the spec is gone; it says the file moved.
• synth's on_round is also called for the accepted round.

New

• ideal --clear-denominators: N / D certified as N, each D
  recorded in cleared and assumed non-zero (relative), checked by
  verify.
• verify --obligation SPEC and certo.obligation: is a certificate
  about THIS obligation -- ideal, nonneg, cover, CNF, LP, or a prove proof
  hypothesis by hypothesis -- with a canonical fingerprint. A valid
  certificate of 0 = 0 standing in for a claim is named.
• Evidence classes on every result, the card and status: proof,
  refutation, identity, sign, counterexample, witness, feasible, LP optimum,
  optimum, relaxation bound, finite check, synthesis, composition, ...
• SynthSpec.scope: the model searched, what is over-approximated, and
  whether counterexamples are realisable, said by the certificate.