docs: dire partout que la lecture par lot n'existe plus

Le contrat publie et l'api-contract etaient traites avec le retrait lui-meme ;
restaient les documents qui decrivaient readUnion comme la primitive de
lecture du paquet, ou qui nommaient le module disparu.

Ce que les lecteurs apprennent maintenant : lire un document, c'est
docs.sparqlQuery ancre dessus, et lire plusieurs documents, c'est cet appel
une fois par document -- avec la decision sur une lecture qui echoue ecrite
au point d'appel. Deux consequences sont dites plutot que decouvertes : une
lecture refusee leve au lieu de rendre une liste vide, et les sujets sous le
prefixe reserve urn:ng-eventually: reviennent dans le resultat, a l'appelant
de les ignorer -- sans aucun gain de droits, les deux registres qu'un
document ordinaire porte etant l'adresse de sa boite et, pour un document
public, la cle que son magasin sert deja a qui la demande.

Les briefs dates ne sont pas touches : ils decrivent un etat de juillet, et
le reecrire falsifierait ce qui avait ete decide alors.

packages/polyfill/src/emulated-verifier/open-repo.ts

@@ -2,7 +2,7 @@
  * open-repo — cold-start repo opening for the ANCHORED read path (polyfill-era).
  *
  * ── The cold-start defect this heals ──────────────────────────────────────
- * The anchored read path (`surface/read-model.ts` `readDoc`,
+ * The anchored read path (`surface/read-document.ts` `readDocumentSubjects`,
  * `shared-wallet/account-registry.ts` `readUserStore`) assumes the target repo is
  * already usable by the verifier — true within the session that CREATED the doc
  * (every `doc_create` opens it), but FALSE on a FRESH session over the same
@@ -19,9 +19,10 @@
  * the verifier: on a persistent profile `Verifier::load` repopulates `self.repos` from
  * user storage at construction (`engine/verifier/src/verifier.rs:535-560`), so the repo
  * is PRESENT but unsynced and the anchored query legitimately matches nothing; and this
- * library's own `readDoc` catches every error and returns `[]`
- * (`surface/read-model.ts:122`), so anything that did throw would reach the caller as
- * emptiness anyway. The fix below is right; the diagnosis written beside it was not.
+ * library's own per-document read caught every error and returned `[]`
+ * (`surface/read-model.ts`'s `readDoc`, until `1.0.0-dev.8` removed it along with the
+ * batch it served), so anything that did throw reached the caller as emptiness anyway.
+ * It no longer does: `surface/read-document.ts` lets the rejection through. The fix below is right; the diagnosis written beside it was not.
  *
  * The circularity that made this self-inflicted: `doc_subscribe` WOULD open the
  * repo, but the reactive layer only subscribes AFTER the listing produced NURIs —