feat: ML-DSA-65, did:key, named hash algorithm, model provenance, log tiles and witnesses

- hashing.algorithm names the hash function in every document; a consumer refuses one it does not implement (doc.hash.algorithm)
- ML-DSA-65 (FIPS 204) is an implemented signature scheme: pure-Python reference in tools/oracle/mldsa.py checked against NIST ACVP vectors, a receipt signed by the new roster key dana, and signature vectors for key generation and a deterministic signature
- roster keys may carry a did:key, which the validator checks against the public key (doc.roster.did), and a witness purpose for parties that cosign log checkpoints
- model provenance: a correction's author and an annotation's generator name the model with provider, version and the hashes of its weights, prompt and parameters, and where it ran
- the transparency log gains the tlog-tiles static layout (fixtures/records/log/), a project settings.log with origin, witnesses and threshold, and an acceptance rule; the fixture checkpoint is cosigned by a witness
- store.sql: roster_keys accepts cose and ml-dsa-65 and gains a did column
- spec chapters 01, 08, 11, 18, 20 and 23, the rationale, glossary, fixture, vector and tool guides updated; stress harness covers ML-DSA

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

tools/README.md

@@ -59,6 +59,7 @@ The oracle exists so that no expected value in this repository is typed by hand.
 
 It favors clarity, and leaves the cryptography and schema validation to established packages.
 Ed25519 (a digital signature scheme) and HKDF come from `cryptography`, and JSON Schema (a format that describes the shape of JSON data) validation from `jsonschema`.
+The VRF of RFC 9381 (`oracle/vrf.py`) and ML-DSA-65 of FIPS 204 (`oracle/mldsa.py`) are written out in plain Python, slow and clear, and checked against the standards' own test vectors.
 The oracle still refuses any schema that uses a keyword outside the subset the schemas are restricted to.
 Canonical JSON goes through Python's built-in JSON encoder, and falls back to an exact RFC 8785 serializer for the values that encoder writes differently: floating-point numbers, integers beyond 2^53 and some non-ASCII member names.