### One Ed25519 rule for every signature

- **SPEC §7 *Signatures*.** Every Ed25519 signature WAI defines is verified strictly: the
  key is its point's one canonical encoding and not of small order, `S` < L, `R` is not of
  small order, and the cofactorless equation holds with `R` compared byte for byte. The
  receipt extensions cite the rule instead of restating it; jwp-receipts §3.1 step 3
  keeps its two reasons, `bad_signer_key` for steps 1 and 2 and
  `signature_verify_failed` for the rest. OER/2's chain signature keeps the rule
  oer-receipts §5 settles.
- **One verifier in wai-rs.** `wai::sig::verify_strict` is the only Ed25519 check written
  in the crate but OER/2's. The video, SSAI, key-release, channel and package receipts
  (both versions), the provenance, ternary, spatial-audio, volumetric, film, score and
  haptics receipts, and a world's session receipt, ops and seal moved onto it; before,
  each read its key with the library's lenient decoder and checked the lenient
  equation, which accepts a key of small order (under the identity, `(R, S) = (B, 1)`
  verifies over every message), a second spelling of a key, and an `R` of small order.
  Claims, JWP groups and the key log, which held the rule in a copy of their own, call
  it too. It builds under the `ed25519` feature, the dependency alone.
- **One verifier in Python.** The claim, JWP, signer, HTTP and packaging verifiers share
  `claim-conformance/_ed25519.py`, the rule written from RFC 8032 with the standard
  library. `pack_verify.py` had checked signatures leniently.
- **Corpora.** Each receipt family's corpus carries the three signatures a verifier
  checking only the equation accepts — the identity as the key with `(R, S) = (B, 1)`,
  the identity spelled `y` = p + 1, and an `R` of small order under the base point —
  and every conforming verifier refuses them: new cases in jwp-conformance,
  signer-conformance and pack-conformance (`mutations/` and `receipts/`); claim- and
  http-conformance had them. No existing vector's expectation changed.

