fix: les trois mutations posent la meme question, et la vue porte ses propres ecritures

L-ASYMETRIE, une fois de plus, et c-est elle le defaut. `delete` et `clear`
interrogeaient `keep`, `add` non - ce qui rendait la phrase publiee vraie par
coincidence : le `add` non garde FABRIQUAIT l-etat que les deux autres ne
traitaient qu-a moitie. Bob plante un objet dans le document d-ALICE, ne le
revoit jamais (la vue le refiltre), la liaison bidirectionnelle le commite
la-bas, puis `clear()` le laisse derriere. Les trois posent maintenant la meme
question ; ce qu-elles repondent differe parce que les membres different :
`delete` a `false`, qui est le mot du contrat Set pour "il n-y etait pas" et qui
est vrai de la vue ; `add` n-a aucune valeur de ce sens, donc il leve.

LA VUE PORTE SES PROPRES ECRITURES. Aucun piege `set`/`deleteProperty`/
`defineProperty` : contre un tableau ordonne, `view[0] = x`, `delete view[0]` et
`view.length = 0` passaient - le dernier defaisant `clear` entierement. Ce qui
est livre est un `readOnlyArray` qui les refuse, donc la production etait
protegee PAR LA CIBLE : la vue s-appuyait sur une garantie qu-elle ne donne pas,
sur une forme qu-elle ne controle pas. C-est l-hypothese empruntee qui est
derriere chaque defaut de cette famille.

LE PROPRIETAIRE EST SERVI. 18 membres declares d-un resultat ordonne levaient
pour celui dont ce sont les donnees, plus `includes` et les sept combinateurs
d-ensemble : une fuite echangee contre une panne. Tout ce que
`@ng-org/alien-deepsignals` declare non mutant est servi sur les objets
lisibles, et un test relit le fichier livre pour que la liste restee ici ne
derive pas.

Aussi : le descripteur d-un ACCESSEUR routait vers la cible ; le faux construit
maintenant les VRAIES collections (`deepSignal`, `readOnlyArray`) au lieu d-un
Set et d-un tableau nus, ce qui le rendait plus permissif que ce qui est livre
apres l-avoir rendu plus correct au round precedent.

.project/concepts/app-contract/polyfill-surface/contract_polyfill-surface.md

@@ -260,7 +260,7 @@ Where a call must first find out whether something already exists — a document
 
 **TWO COPIES OF THIS PACKAGE IN ONE APPLICATION MISBEHAVE SILENTLY, and nothing here can detect it.** What this package remembers it keeps in the package itself, not in any handle you hold: which documents are subscribed and who is listening for them, which identity the session settled on, which documents are open. None of that is shared between two copies. An application that ends up with two therefore runs two of everything — a document subscribed through one copy is invisible to the other, so changes to it simply never arrive; and the identity settled in one is not the identity the other acts as, so the same call writes as one user or the other depending on which copy it reached. Nothing raises, nothing warns, and no call can report it: from every entry point a second copy is indistinguishable from the first, and the symptoms surface far from the cause as missing updates and writes attributed to the wrong person. This is a packaging property, not a behaviour to code around — **declare this package once, as one dependency of the application**, and let your own code and every library built on it resolve to that copy. A library that builds on this package should declare it a *peer* rather than a dependency for exactly this reason, so that the application remains the one place it is named.
 
-**No unfiltered read through `useShape`, and no way round it through the object it hands back.** What the call returns is NextGraph's own result, filtered: `data` and `promise` carry only items in documents you hold the key for, `isLoading` passes through, the two page commands run and whatever they hand back is held to the same rule as any other member, and `subscription` - the ORM's own handle, which reads and writes with no capability filter at all - is refused out loud rather than handed on. Any other member of that object is refused too unless what is behind it is a plain scalar, which is how a member a later `@ng-org/orm` adds is decided before anyone has seen it: whatever can carry an item is an object or a function, and both refuse. Inside `data`, every member that yields items is filtered, and an ordered result addresses and counts the items you may read: `size`, `length`, an index, `Object.keys`, `in` and `JSON.stringify` all agree, and none of them says how many you may not. **Reading a member's DESCRIPTOR answers exactly what reading the member answers**, which is not a detail: `Object.getOwnPropertyDescriptor` - and the spread, `Object.entries` and console inspection built on it - reads a property without going through the view's own read, so a refused member throws there too rather than handing its value over. **A mutation reaches the collection underneath, and neither hands back nor acts past what the view shows.** Writing is not broken - `add` reaches the document and the reactivity it drives - but `add` hands back the VIEW rather than the collection, because `Set.prototype.add` returns the collection so calls can be chained and chaining onto the unfiltered one is the whole leak; `delete` removes only an item the view shows, which is the same question `has` already declines to answer about; and `clear` empties the view rather than the collection every identity shares. A document reached through that view alone, read nowhere else first, does not appear.
+**No unfiltered read through `useShape`, and no way round it through the object it hands back.** What the call returns is NextGraph's own result, filtered: `data` and `promise` carry only items in documents you hold the key for, `isLoading` passes through, the two page commands run and whatever they hand back is held to the same rule as any other member, and `subscription` - the ORM's own handle, which reads and writes with no capability filter at all - is refused out loud rather than handed on. Any other member of that object is refused too unless what is behind it is a plain scalar, which is how a member a later `@ng-org/orm` adds is decided before anyone has seen it: whatever can carry an item is an object or a function, and both refuse. Inside `data`, every member that yields items is filtered, and an ordered result addresses and counts the items you may read: `size`, `length`, an index, `Object.keys`, `in` and `JSON.stringify` all agree, and none of them says how many you may not. **Reading a member's DESCRIPTOR answers exactly what reading the member answers**, which is not a detail: `Object.getOwnPropertyDescriptor` - and the spread, `Object.entries` and console inspection built on it - reads a property without going through the view's own read, so a refused member throws there too rather than handing its value over. That holds for an ACCESSOR as much as for a value: the getter you are handed reads through the view, and its setter is refused. **A mutation reaches the collection underneath, and neither hands back nor acts past what the view shows.** Writing is not broken - your own `add` reaches the document and the reactivity it drives. **All three ask the same question**: `add` into a document you hold no key for THROWS (it returns the collection whether or not it did anything, so it has no value meaning "that did not happen"), `delete` of an item the view does not show answers `false` - the Set contract's own word for "it was not there", and true of the view - and `clear` empties the view rather than the collection every identity shares. `add` hands back the VIEW rather than the collection, because `Set.prototype.add` returns the collection so calls can chain and chaining onto the unfiltered one gives it away entirely. **Writing to the collection's own properties is refused** - `data[0] = x`, `delete data[0]`, `data.length = 0` - on this view's own account rather than because the ordered collection upstream happens to refuse them too. **Every member `@ng-org/alien-deepsignals` declares non-mutating answers**, computed over the items you may read: the iterator helpers, the array reads (`at`, `slice`, `join`, `indexOf`, `toSorted`, `with`) and the ES2025 set combinators (`union`, `difference`, `isSubsetOf`). A document reached through that view alone, read nowhere else first, does not appear.
 
 **`isLoading` does not mean what its name says, and the fault is upstream's.** `@ng-org/orm`'s declaration describes it as "`true` when no data is available yet"; the hook that ships computes it as the subscription's `isReady`, which is the inverse. Both artifacts were read and they disagree. This package forwards the value it is handed rather than correcting it, because a layer that quietly improves the target teaches you a behaviour you would have to unlearn. **Branch on `data === undefined`**, which is unambiguous, and treat `isLoading` as unusable until upstream settles it.
 
@@ -294,7 +294,9 @@ What each level means here, in this package's own terms:
 - **The two arguments are the SDK's own types**, where the signature took `unknown` for both. `useShape(shapeType: ShapeType<T>, conf: RdfOrmConfig<T> | string | undefined)`, which is what the surface already said the pair was. A caller passing the SDK's shape and config compiles unchanged; one passing something else now does not, which is why this counts.
 - **`size` and `length` count what you may read, and so does every other way of asking.** An ordered config (`orderBy`) makes the collection an array, which says how many items it holds in four places - `length`, `Object.keys`, `in`, and the descriptor of each index - and only the first was filtered. `data[0]` now names the first item you may read rather than the first the engine returned, and the positions past them do not exist.
 - **A member's DESCRIPTOR answers what reading it answers.** `Object.getOwnPropertyDescriptor(result, "data")` returned the collection UNFILTERED, and `...(result, "subscription")` the handle that reading it refuses: that call does not go through the view's own read. Neither does a spread, `Object.entries`, `JSON.stringify` or a console inspection, so all of them were reading round the filter. They now read through it - which also means `{...result}` and `console.log(result)` throw on `subscription`, where they used to print it. Log `data`.
-- **A mutation no longer hands back the collection, nor acts past the view.** `add` returned it - `Set.prototype.add` returns `this` so calls chain, measured on the plain `Set` and on the real `DeepSignalSet` alike - so `view.add(x)` gave every identity's items to a caller whose every way IN was filtered, through the first member the ORM's own example reaches for. It now hands back the view. `delete` refused nothing and removed an item the view declines to confirm the existence of; it now removes only what the view shows. `clear` emptied the collection every identity shares; it now empties the view. **Writing still reaches the document** - that is the one thing that must not change, and `e2e/orm-live-read.ts` measures it against the deployed broker.
+- **A mutation no longer hands back the collection, nor acts past the view, and all three ask the same question.** `add` returned the collection - `Set.prototype.add` returns `this` so calls chain, measured on the plain `Set` and on the real `DeepSignalSet` alike - so `view.add(x)` gave every identity's items to a caller whose every way IN was filtered, through the first member the ORM's own example reaches for. It now hands back the view, and it now REFUSES an object naming a document you hold no key for: ungated, it let you plant an object into someone else's document, never see it again, and have the two-way binding commit it there. `delete` removed an item the view declines to confirm the existence of; `clear` emptied the collection every identity shares. **Your own writes still reach the document** - that is the one thing that must not change, and `e2e/orm-live-read.ts` measures it against the deployed broker.
+- **A write to the collection's own properties is refused.** `data[0] = x`, `delete data[0]` and `data.length = 0` all went through against a collection that allowed them; the last defeated the emptying rule outright. The view refuses them itself now, rather than relying on the ordered collection upstream refusing them for it.
+- **The members upstream declares non-mutating answer again.** Eighteen array reads on an ordered result, plus `includes` and the seven set combinators, were throwing for the holder whose data it was - a leak traded for an outage. They are served over the items you may read.
 - **An ordered result yields indices where it used to yield items.** `keys()` handed back items, `entries()` handed back `[item, item]` and `forEach` handed the item as its second argument - the Set contract, applied to an array. No leak, and wrong output on your own data.
 - **Unchanged**: the read still spends no round-trip asking a public store for a key, a document you have read nowhere else still does not appear, and nothing about `useShapeQuery`, `getObjects` or `insertObject` moves.