fleetd #551 rework (comment 17058): fix TIMED_OUT_QUEUED javadoc for ATTEMPTED

Javadoc-only change. #551 added Injector.Cancellation.ATTEMPTED, which
MessageService.send's timeout path folds into Outcome.TIMED_OUT_QUEUED
alongside CANCELLED and NOT_DELIVERED (the collapse itself is unchanged
behaviour and is being tracked as a separate follow-up ticket).

TIMED_OUT_QUEUED's javadoc — landed by #513 to state the routes that
reach it — named only two routes and said "on every route it will not
arrive later", with a "may already hold a partial paste" caveat. Both
claims are now stale: ATTEMPTED is a third route, and because
agent.prompt pastes AND submits in one call, that route may mean the
target holds a complete, already-submitted turn and is working on it
right now.

Names all three routes, says which one is uncertain, and drops the
now-false blanket claim. No behaviour change.

fleetd/src/main/java/dev/ltms/fleet/msg/MessageService.java

@@ -94,16 +94,22 @@ public final class MessageService {
         TIMED_OUT_WORKING,
         /**
          * Timed out with no confirmed delivery. Despite the name, this does not mean the message
-         * is sitting in a queue — on every route it will not arrive later. {@link #send} reaches
-         * this outcome through {@link Injector#cancel}, whose result tells the routes apart:
+         * is sitting in a queue. {@link #send} reaches this outcome through {@link Injector#cancel},
+         * whose result tells three routes apart:
          * {@link Injector.Cancellation#CANCELLED} means the message was still queued and this call
-         * removed it, so the target saw nothing; {@link Injector.Cancellation#NOT_DELIVERED} means
-         * an earlier attempt already decided the message's fate — the injector's call to the
-         * target's terminal ({@link dev.ltms.fleet.herdr.AgentControl#send}) threw, or the queue
-         * was cleared because the target never became ready or was abandoned — and {@code cancel}
-         * is only reporting that pre-existing state. On the failed-attempt route the terminal may
-         * already hold a partial paste from before the call threw, so only the {@code CANCELLED}
-         * case establishes that the target saw nothing.
+         * removed it, so the target saw nothing and it will not arrive later;
+         * {@link Injector.Cancellation#NOT_DELIVERED} means nothing was ever sent — the queue was
+         * cleared because the target never became ready or was abandoned, or the injector's call to
+         * the target's terminal ({@link dev.ltms.fleet.herdr.AgentControl#send}) failed with a herdr
+         * error that this codebase already treats as a confirmed absence — so this route too
+         * establishes that the target saw nothing and it will not arrive later; but
+         * {@link Injector.Cancellation#ATTEMPTED} (fleetd #551) means that call was made and its
+         * outcome is unknown. {@code agent.prompt} pastes <em>and submits</em> in one call, so on
+         * this route the target may hold a complete, already-submitted turn and be working on it
+         * right now — {@link Outcome#TIMED_OUT_WORKING}'s meaning, reported here as
+         * {@code TIMED_OUT_QUEUED} only because this caller never observed the pickup. Only
+         * {@code CANCELLED} and {@code NOT_DELIVERED} establish that the target saw nothing;
+         * {@code ATTEMPTED} does not.
          */
         TIMED_OUT_QUEUED,
         /** Another send to this session was in flight for the whole window. */