docs: dire l'observation continue, sa limite, et ce qu'ensureIdentity ne promet pas

.project/concepts/sign-in/knowledge_settling-is-not-connecting.md

@@ -8,7 +8,7 @@ summary: Deciding which identity acts needs no session; connecting does — conf
 Two acts of different nature hide behind "sign in":
 
 - **`settle`** — decide which identity is acting, from the URL, from storage, or by asking at the `barrier`, then persist it. Pure DOM and storage. **No session required.**
-- **connect** — put back in that identity's hands everything it can already open: what it OWNS as well as what was shared with it, then drain its queues. **Requires a live session.**
+- **connect** — put back in that identity's hands everything it can already open: what it OWNS as well as what was shared with it, drain its queues, and then keep applying what arrives in them for as long as it stays connected. **Requires a live session.**
 
 The wallet keeps those two in different places, and connecting once replayed only the second — so an application that reloaded and went straight to a document it had made itself was refused its own document. Whatever else changes here, connecting must replay **every** durable register, not the one that happens to be read on the path being tested.
 
@@ -49,3 +49,13 @@ A deposit that cannot be applied is not consumed by failing. So a single unusabl
 The distinction to keep: **reaching** the queues, and the restore itself, are infrastructure — if they fail, the session genuinely cannot proceed, and rejecting is right. **Applying one item** is data — it must be reported loudly, the remaining queues must still be drained, and the session must still be granted.
 
 The general shape, worth carrying to any similar rule: when a blanket "every failure surfaces" is imposed, ask which failures are *retried by simply trying again later* and which are *permanent for the actor*. The permanent ones must never gate something the actor cannot otherwise obtain.
+
+## Connecting does not end when the drain does
+
+The drain is the backlog; being connected is a regime. An identity that stays connected has its inboxes watched throughout, so a deposit made in front of it is applied as it arrives rather than waiting for a reload, and an inbox opened later in the session joins the watched set.
+
+That third step runs whatever became of the two before it, and the failure it was added for says why. A restore that rejected used to skip it, leaving an identity connected — recording who acts is synchronous and had already taken effect — with nothing watching its inboxes for the rest of the session. One broker hiccup while signing in then cost that person every deposit made from then on, in silence, long after the broker had recovered. What the caller is told has not moved: reaching the queues still rejects. What changed is that being connected now *means* being watched, whatever the connection made of its own work.
+
+The counterpart is that the watching belongs to one identity and dies with it. Recording a different identity — or none, which is a disconnection and not merely "no new work" — stops it, because every step of it resolves the current holder as it runs: left going, it would read the previous identity's registers under the new one and file the previous one's `ReadCap`s into the new one's hands. Whoever connects next starts their own.
+
+There is deliberately no timer anywhere in this: the regime is push-driven, and its known cost — a watch that failed to open is re-opened only by a later event, so a session that only reads never gets it back — is stated to applications under the contract's non-guarantees rather than papered over with polling.