Closes #422.

Hypothesis

Given a signed PromotionReceipt or sealed-field-authenticity check (sealedFieldsAuthentic
in replay.ts, validAttestation in multigeneration-proof.ts) that compares a live numeric
field against its canon()-encoded signed counterpart, when canon() is hardened to encode
NaN, Infinity, and -Infinity as distinct, unambiguous literal tokens (rather than
collapsing them to null via JSON.stringify), then a live field tampered between a
non-finite value and null (or between two non-finite values) is detected, subject to
byte-identical output for every existing finite/string/bool/null/array/object value and 0
regressions on every legitimately-signed existing receipt. Frozen before implementation.

Candidate

packages/flywheel/src/receipts.ts's canon() fell through to JSON.stringify(v) for
scalars. JSON.stringify(NaN) === JSON.stringify(Infinity) === JSON.stringify(-Infinity) === JSON.stringify(null) === "null" (ECMA-262's own behavior), so any canon-EQUALITY check
inherited a 4-way collision at exactly the values it exists to protect. Fix: encode
NaN/Infinity/-Infinity as distinct unquoted literal tokens before falling through to
JSON.stringify — none of those tokens is valid JSON syntax for any string/number/bool/null,
so none collides with any other value canon() produces. 76 insertions / 1 deletion, 2 files
(receipts.ts + its test file).

Evaluation Receipt

• Baseline (git stash -- packages/flywheel/src/receipts.ts): 3/60 new assertions fail
  non-vacuously — the exact predicted 4-way-collision and the exact predicted false-
  "authentic" verdicts on two tampered commits (primaryDelta NaN→null, anchorScore
  Infinity→NaN, both with no signing key).
• Candidate: 60/60 pass. Full @metaharness/flywheel suite 146/146, 0 regressions.
  tsc --noEmit clean.
• All 7 real committed ReplayBundle/proof-bundle JSON files in-repo re-verify
  ACCEPTANCE: PASS, byte-identical (evals-math ×3, radio, darwin-mode/swebench,
  kimi-k3-harness, experiments/signal-flywheel).
• Downstream sweep (11 packages): 1465 passed / 16 skipped / 1 failed — the 1 failure
  (avo/__tests__/openrouter-live.test.ts) is a live OpenRouter HTTP 404 on a deprecated
  model ID, confirmed environmental, unrelated to this diff.
• npm audit --omit=dev --audit-level=high: 0 vulnerabilities.

Baseline Comparison

See Evaluation Receipt above — baseline (main, unpatched canon()) vs. candidate, same
test file, same real-committed bundles, same downstream suite.

Darwin Lineage

DARWIN=not_applicable — a canonicalization-primitive correctness fix has no tunable
parameter space; not one of ADR-071's seven Darwin-eligible mutation surfaces.

Flywheel Evidence

Full OBSERVATION → MEASUREMENT → INFERENCE → HYPOTHESIS → DECISION record:
docs/dream-cycle/2026-10-21-evidence.md.

Reward Hack Check

Clear. Diff is additive-only on the test file; no existing assertion/threshold/gold data
weakened, no test skipped, no cost hidden. Independently confirmed by a fresh adversarial
critic (own reproduction, not taken on faith).

Security Review

This candidate is the security hardening itself — closes a tamper-evidence-defeating value
collision in the package's core signed-receipt trust primitive. RFC 8785 (JSON
Canonicalization Scheme) forbids non-finite numbers in canonical JSON for exactly this
reason; the Rust json-canon crate documents the identical pitfall independently. See
docs/dream-cycle/2026-10-21-gist.md for the full competitor/citation table.

Regression Analysis

0 regressions at every tier measured (package suite, real committed bundles, downstream
11-package sweep, tsc, npm audit). The 1 downstream failure is a live-network
environmental flake in an unrelated file (OpenRouter model deprecation), not caused by this
diff.

ADR

None filed — this is a correctness fix to an existing documented primitive (ADR-274/
ADR-317/ADR-318's canonicalization/receipt model), not a new architectural decision.

Research Gist

docs/dream-cycle/2026-10-21-gist.md — SOTA research, competitor comparison (in-toto/
Sigstore, RFC 8785 reference implementations, Darwin Gödel Machine, LangGraph/Microsoft
Agent Framework/CrewAI, K-Veritas), full citations.

Issue

#422

Witness

session_commit : e0dfd44da72b7adfb7c57fdd42d124be58ed7086
report_sha256   : fd618728ac28bb77bc8ebca54554cf6768c64740ba7a49287e15ebc1eac4d366
witness         : 476f5aa181419efe023134004aed5de00e63c47dcfa42ca8dfd98948cda554bb

Merge Policy

Human review required. Do not self-merge. Do not autonomously promote Flywheel state.

Disclosed, not fixed in this PR (future-night candidates): packages/avo/src/flywheelGate.ts
and packages/turn-credit/src/receipt.ts ship their own separate, still-colliding canon()
duplicates; validate-bundle.ts's fail-closed numeric-domain gate lives only in the CLI path,
not in verifyReplayBundle/verifyMultiGenerationEvidence themselves.

Generated by Claude Code