feat: minted keys, VRF seeds, RFC 9162 proofs, history roots, tag URIs and a transparency log

Keys (spec/02 §2.4), the rule paperstack settled on:
- A work key is a Scholar-style citation key, a hyphen and the first four
  Crockford base32 characters of SHA-256("scienting-key/1:" + identity),
  where the identity is the first of doi, arxiv, isbn, pmid, pmcid and
  openalex in same_as, else the folded title, year and family name. A
  collision lengthens the later key by two characters; a key is minted
  once and never recomputed. A document key adds .si, .v<seq> or .<type>
  for versions other than the version of record.
- Every fixture key is now minted (hale2026harmonic-damb,
  okafor2025solvent-acth, writer2027fixed-ynr7.v3, tiny2026tiny-j4qm), so
  every node and record ID was re-minted and the docs rewritten to match.
  The validator checks the document key against the work key and version
  (doc.key.work) and the hash part against the identifier (doc.key.suffix).
  vectors/keys.jsonl pins the cases paperstack's tests pin.

Review:
- Spot-check seeds are ECVRF-EDWARDS25519-SHA512-TAI proofs (RFC 9381),
  implemented in tools/oracle/vrf.py in plain Python and reproduced
  against the RFC's Example 16; the sample ranks by the VRF output. The
  earlier Ed25519 seed could be ground by a dishonest checker.
- RFC 9162 inclusion and consistency proofs (crypto.inclusion_path,
  verify_inclusion, consistency_proof, verify_consistency) with
  scienting-proof/1, vectors/proofs.jsonl and two fixture records.
- document.json carries `history`, the root over the corrections, with
  the empty-tree hash for none (spec/11 §11.5, rule doc.history).
- A provisional transparency log (spec/23): log entries, signed-note
  checkpoints with key hashes as transparency logs share them, the rule
  that a logged revocation beats a self-asserted time, and vectors.
- Reserved signature schemes cose and ml-dsa-65 (spec/08 §8.4).

Identifiers and text:
- urn:scienting: becomes tag:scient.ing,2026: (RFC 4151), since the URN
  namespace was never registered.
- Unicode 16.0 is pinned for normalization and categories (spec/01 §1.4);
  the checker refuses another version.

Checking:
- check.py: keys, proofs, VRF and checkpoint vectors; the proof and
  checkpoint records; a check that every ID and hash the prose quotes
  exists in the fixtures or vectors; three more broken packages
  (history-wrong, key-suffix, key-work).
- stress.py: key, VRF, proof and checkpoint properties.
- Docs: a keys section in the concepts and FAQ, rationale entries for
  keys, VRF, proofs, tag URIs and the Unicode pin, a "Looking ahead"
  section, media-type registration and OCI distribution notes.

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

spec/06-anchors.md

@@ -6,22 +6,25 @@ An address names a node, optionally pinned to a hash and narrowed to a span:
 
 ```abnf
 address  = [store "/"] key "#" node ["@" pin] ["[" start ":" end "]"]
-store    = key
-key      = lowalnum *(lowalnum / "." / "_" / "-")
-node     = key                      ; a node ID or an alias
+store    = lowalnum *(lowalnum / "." / "_" / "-")
+key      = workkey *("." lowalnum *(lowalnum / "-"))   ; a document key (2.4)
+workkey  = LOWER *lowalnum "-" 4*51BASE32
+node     = lowalnum *(lowalnum / "." / "_" / "-")      ; a node ID or an alias
 pin      = 6HEXLOWER                ; the first six digits of a node_hash
 start    = "0" / (%x31-39 *DIGIT)
 end      = "0" / (%x31-39 *DIGIT)
-lowalnum = %x61-7A / DIGIT
+lowalnum = LOWER / DIGIT
+LOWER    = %x61-7A
+BASE32   = DIGIT / %x61-68 / %x6A-6B / %x6D-6E / %x70-74 / %x76-7A   ; Crockford, lowercase
 ```
 
 `start` is not greater than `end`, and both are code-point offsets into the plain projection of the node in the pinned state.
 
 | Example | Names |
 | --- | --- |
-| `cornell1995second#k3m9q2a` | A sentence, whatever its current text. |
-| `cornell1995second#k3m9q2a@4f1a0c` | That sentence as it read when its `node_hash` began `4f1a0c`. |
-| `cornell1995second#k3m9q2a@4f1a0c[12:57]` | Code points 12 to 57 of its plain projection in that state. |
+| `cornell1995second-saqk#k3m9q2a` | A sentence, whatever its current text. |
+| `cornell1995second-saqk#k3m9q2a@4f1a0c` | That sentence as it read when its `node_hash` began `4f1a0c`. |
+| `cornell1995second-saqk#k3m9q2a@4f1a0c[12:57]` | Code points 12 to 57 of its plain projection in that state. |
 | `smithlab/cornell1995second#k3m9q2a` | The same sentence in the `smithlab` store. |
 
 On the web the node ID is the fragment: `…/smithlab/cornell1995second#k3m9q2a` lands on the sentence.
@@ -102,7 +105,7 @@ The result is `{result, node, node_hash?, span?, drift?, via?, reason?}`: the ou
 A `moved` or `reattached` anchor is re-pinned to the live node, and the move is recorded.
 
 Checks are stricter than readers: an extract is a span or leaf anchor and never accepts `changed-below`, because a check is about exact words.
-`resolve.jsonl` resolves seventeen anchors made at revision 0 against `fixtures/packages/hale2026harmonic` at revision 12, with every outcome.
+`resolve.jsonl` resolves seventeen anchors made at revision 0 against `fixtures/packages/hale2026harmonic-damb` at revision 12, with every outcome.
 
 ## 6.6 Drift