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>

spec/11-corrections.md

@@ -28,7 +28,7 @@ Runs are made canonical after every operation, and the result MUST satisfy every
 | Property | Holds |
 | --- | --- |
 | `evidence` | At least one item: `crop`, `witness` or `source-file` by SHA-256, or `person`. |
-| `author` | `{key}` for a person in the roster, or `{model, run}` for a model's session. |
+| `author` | `{key}` for a person in the roster, or `{model, run}` for a model's session, where `model` is `{name, provider?, version?, weights?, prompt?, parameters?, processor?}`: the model's name, who served it, its version, and SHA-256 of the weights, the instructions and the sampling parameters it ran with, as far as the team can obtain them, and where it ran ([14](14-rights.md)). |
 | `reason`, `at` | Why, and when. |
 
 A proposal, such as one a tool makes, carries these and `status: "proposed"`, and no applied fields.