docs: fusionner le commentaire duplique sur la souscription bootstrap

Deux blocs disaient « la souscription est maintenue vivante pour la
session », l'un accroche a onSetupFailed et l'autre a l'appel de
souscription - exactement le defaut de commentaire orphelin que cette
tache devait corriger ailleurs.

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

@@ -405,13 +405,6 @@ export async function openRepoUnguarded(nuri: Nuri): Promise<void> {
         }
         stopWaiting();
       };
-      // The bootstrap subscription is kept ALIVE for the session — holding it open
-      // is the whole point. We wait for the FIRST `State` event specifically (the
-      // barrier), NOT any push: the platform pushes `TabInfo` before `State`, and
-      // resolving on `TabInfo` would return before the real sync barrier.
-      // Unguarded on purpose: the caller already decided. `ensureRepoOpen` applied
-      // rule 2 above; `ensurePhysicalRepoOpen` is the machinery's door and is not
-      // subject to the boundary at all (see physical.ts).
       // A failed establish is REPORTED, and `subscribe.ts` offers this channel precisely
       // so that a caller can retry. Let the listener go, so the next caller opens a NEW
       // subscription rather than joining a fan-out that is not going to push. There is no
@@ -437,7 +430,14 @@ export async function openRepoUnguarded(nuri: Nuri): Promise<void> {
       };
       // The bootstrap subscription is kept ALIVE for the session - holding it open is the
       // whole point. It is a LISTENER on the document's one real subscription, which is why
-      // it says nothing about whether that subscription exists.
+      // it says nothing about whether that subscription EXISTS: that is {@link docChannel}'s
+      // answer, and the two together are what `openRepoUnguarded` asks above.
+      //
+      // We wait for the FIRST `State` event specifically (the barrier), NOT any push: the
+      // platform pushes `TabInfo` before `State`, and resolving on `TabInfo` would return
+      // before the real sync barrier. Unguarded on purpose - the caller already decided:
+      // `ensureRepoOpen` applied rule 2, and `ensurePhysicalRepoOpen` is the machinery's door
+      // and is not subject to the boundary at all (see physical.ts).
       mine.release = subscribeDocUnguarded(
         nuri,
         (_r, type) => {