docs: le lecteur du barriere dit que les quatre valeurs sont derivees

Le commentaire de `namedDocumentsArrived` decrivait `open-repo` comme
gardant trois valeurs, et disait que l'attente "resout sur le State ou
sur le repli, et chacun pose sa propre valeur" - plus vrai depuis que
rien ne les stocke.

packages/polyfill/src/surface/use-shape-query.ts

@@ -441,18 +441,21 @@ export function useShapeQuery<T extends BaseType = BaseType>(
    * Has every document the scope NAMES actually ARRIVED - not merely "may this holder
    * reach it", which is a different question and the only one this module used to ask?
    *
-   * `emulated-verifier/open-repo.ts` keeps three values apart for exactly this reader, and
-   * which of them counts as an answer is the whole of the decision:
+   * `emulated-verifier/open-repo.ts` DERIVES four values for exactly this reader - since
+   * `1.0.0-dev.10` nothing stores them, they are read off the document's one real
+   * subscription - and which of them counts as an answer is the whole of the decision:
    *
-   *   - `"synced"` - the first `State` came. THE truth signal: zero rows means zero
-   *     objects, and that is the success this surface exists to publish.
-   *   - `"timed-out"` - the bounded fallback fired with no `State`. Opened best-effort,
-   *     sync unconfirmed. The document may hold anything and this read has no standing to
-   *     call it empty. This is the case the barrier was added for and did not close.
-   *   - `"syncing"` - unreachable once the open has resolved (it resolves on the `State`
-   *     or on the fallback, and each sets its own value); refused anyway, because if it
-   *     ever IS reached then the barrier demonstrably was not.
-   *   - `"unknown"` - "never requested, or the fake-ng no-op path: no `State` semantics".
+   *   - `"synced"` - a `State` has arrived on the channel standing NOW. THE truth signal:
+   *     zero rows means zero objects, and that is the success this surface exists to publish.
+   *     Read off the channel rather than remembered, so it cannot survive that channel's
+   *     teardown - which is what used to let a second `configure(...)` answer a success for a
+   *     document nothing was subscribed to.
+   *   - `"timed-out"` - opened, and no barrier to show for it: the bounded fallback fired, the
+   *     subscribe was refused, or the channel was taken away. Sync unconfirmed. The document
+   *     may hold anything and this read has no standing to call it empty.
+   *   - `"syncing"` - the open is still inside its bounded wait; refused for the same reason,
+   *     and if it is ever seen here the barrier demonstrably was not crossed.
+   *   - `"unknown"` - "never opened there, or the fake-ng no-op path: no `State` semantics".
    *     **Passes, deliberately.** There is no barrier to have missed where there are no
    *     barrier semantics, and an `ng` without `doc_subscribe` is the whole unit suite and
    *     every early path. Treating it as not-synced is the inert regression this line of