hotato 1.15.0

Added

• hotato prove: one command, one release proof. Composes the evidence
  lanes you already ran into a single fail-closed verdict with a portable
  receipt: --contracts re-scores contracts through contract verify's own
  logic, --suite runs a conversation-test suite, --before/--after scores
  the battery rollup through hotato verify (with its min-n refusal), and
  --gauntlet runs the bundled stress suite. It adds no new scoring engine.
  Overall is pass only when every activated lane passed; any failure fails the
  proof, and a lane that could not support its claim is inconclusive and exits
  non-zero, so CI never reads "could not tell" as green. Writes
  proof.json (schema hotato.proof.v1) plus proof.md: verdicts, counts,
  relative names, and sha256 digests only, with a content address that
  regenerates identically under a pinned SOURCE_DATE_EPOCH.
• docs/LIFECYCLE.md: the whole loop on one page. Observe, catch, pin,
  test, prove, and the production edge that feeds the next loop, with every
  command mapped to its step.

Changed

• The story is the loop. README, the docs index, and docs/COMPARE.md are
  restructured around one sentence: every production failure becomes a portable
  test, every candidate runs against it, and every release carries evidence.
  The comparison page now walks the lifecycle side by side with hosted
  platforms and states the three structural differences (free at any scale,
  verdicts reproducible enough to gate a build, data that stays yours).
• Concrete positioning. Every surface leads with "Local-first testing and
  observability for AI agents"; the positioning-lockstep test enforces the new
  line and retires the vague platform noun.