docs: aligner la doctrine ORM sur les paquets reellement installes

Les quatre paquets @ng-org sont deja a leur derniere version publiee
(web alpha.14, orm alpha.21, shex-orm alpha.9, alien-deepsignals
alpha.13) : le refresh ne deplace rien. Ce qui restait faux, c'est la
doctrine, laissee en arriere par le refresh precedent.

Le point de fond : le checkout epingle de nextgraph-rs (213338f6)
declare orm alpha.18, donc la source citee est TROIS versions derriere
les paquets contre lesquels ce depot compile. La ou les deux divergent,
les leaves nomment desormais les deux.

Faits corriges, tous verifies dans node_modules :

- les versions installees annoncees en tete de leaf (alpha.19/13/11)
- OrmSubscription est renomme RdfOrmSubscription dans alpha.21, fichier
  compris (connector/RdfOrmSubscription.ts)
- alpha.21 exporte removeObject(graphNuri, subjectIri), absent de la
  source ; sa propre documentation se contredit sur sa portee
- getOrCreate prend un RdfOrmConfig, plus un Scope nu, et l'instance
  gagne mode/isReady/addChangeListener/nextPage/previousPage
- Scope.graphs est REQUIS dans alpha.21, et les deux axes lisent [] en
  sens INVERSE : graphs [] = ensemble vide, subjects [] = aucun filtre.
  La table le dit explicitement, c'est le piege deja paye une fois
- la lecture ORM live DEMARRE contre le deploiement (5 passed, 0 failed,
  pret en 13ms) ; le lien mort vers bug_useshape-live-read-needs-a-newer
  -broker disparait, ainsi que le "exit non-zero attendu" de la suite

Ce qui n'est PAS affirme : que le where/orderBy/pageSize d'alpha.21
atteigne le moteur. A 213338f6 start_orm construit encore son config a
partir de json!({}) derriere un TODO, donc la richesse est exprimable au
niveau 3 et jetee au niveau 1. Non mesure, donc non ecrit.

.project/concepts/app-contract/knowledge_what-a-read-scope-is-upstream.md

@@ -1,7 +1,7 @@
 ---
 type: knowledge
 summary: What the target offers for reading many objects — a graph is one document, a store's graph holds only its containment triples, and scoping a read by store is not expressible at all
-last_checked: 2026-09-16
+last_checked: 2026-09-21
 ---
 
 # What a read scope is upstream
@@ -10,7 +10,16 @@ Read at the source in `nextgraph-rs` (`213338f6`). Every claim points at a symbo
 
 ## The type, and the two axes it filters on
 
-`Scope = { graphs?: string[] | string; subjects?: string[] }` (`sdk/js/orm/src/types.ts`), normalised by `normalizeScope` into `{ graphs: string[]; subjects: string[] }`. Its own documentation states the edges: `["did:ng:i"]` or `[""]` means the whole dataset, while `[]` or `undefined` returns **no objects at all**. Two axes, no third.
+`Scope = { graphs?: string[] | string; subjects?: string[] }` (`sdk/js/orm/src/types.ts` at `213338f6`), normalised by `normalizeScope` into `{ graphs: string[]; subjects: string[] }`. **In the installed `@ng-org/orm@0.1.2-alpha.21`, `graphs` is REQUIRED** (`graphs: string[] | string`, `dist/types.d.ts`); `subjects?` stays optional. A caller that omitted `graphs` no longer compiles.
+
+**The two axes read `[]` in OPPOSITE directions, and this is the trap.** Upstream documents each field separately, and they do not agree:
+
+| field | `["did:ng:i"]` or `[""]` | `[]` or `undefined` |
+|---|---|---|
+| `graphs` | the whole dataset | **no objects at all** - the EMPTY set |
+| `subjects` | n/a | **no filtering** - every subject |
+
+So `{ graphs: [], subjects: [] }` returns nothing, and it is `graphs` alone that decides it. Reading the pair as symmetrical is how a read that should have been unscoped becomes a read that matches nothing, silently, since a shape query matching nothing is indistinguishable from a scope holding nothing. Two axes, no third.
 
 ## A `graphs` entry is one document's graph, never a set of them
 
@@ -48,7 +57,7 @@ That is `declared-not-wired` in the taxonomy of [[no-divergence-from-nextgraph]]
 
 ## "Not ready" and "ready and empty" are distinguishable — one level down
 
-`OrmSubscription` (`sdk/js/orm/src/connector/GraphOrmSubscription.ts`) is exported from the package entry — `core.ts`, which `@ng-org/orm` resolves `.` to — and carries a public `readyPromise` getter. So at that level the two states **are** distinguishable. The React `useShape` adapter drops the distinction: it returns a `DeepSignalSet` and documents it as *"the orm objects or an empty set, if still loading"*. The gap is between level 3's class and level 3's hook, not between us and the target.
+`OrmSubscription` (`sdk/js/orm/src/connector/GraphOrmSubscription.ts`) is exported from the package entry — `core.ts`, which `@ng-org/orm` resolves `.` to — and carries a public `readyPromise` getter. In the installed alpha.21 both the symbol and its file are renamed, to `RdfOrmSubscription` and `connector/RdfOrmSubscription.ts`, and it gains an `isReady` getter that answers the same question without awaiting. So at that level the two states **are** distinguishable. The React `useShape` adapter drops the distinction: it returns a `DeepSignalSet` and documents it as *"the orm objects or an empty set, if still loading"*. The gap is between level 3's class and level 3's hook, not between us and the target.
 
 ## What this package does instead