Task Wait Qualifiers rule 6: owner-return waits use blocked_on: message-from:<agent>

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

workplans/CUST-WP-0074-qualified-wait-states.md

@@ -94,7 +94,9 @@ Rules:
 6. A wait on a repo that has no workplan id yet stays Case A with the
    repo named in `blocking_reason` and the workplan-level `blocked_on:`
    field (C-25). Upgrade to a `depends_on` id as soon as the owner
-   returns one.
+   returns one. *Revised during T05 (2026-09-28): the task block carries
+   `blocked_on: message-from:<agent>` instead; C-39 accepts it, the hub
+   read model does not yet (reports `unqualified`) — follow-up in T02.*
 
 The workplan-level `depends_on` (C-20) is unchanged. Task-level
 `depends_on` is the new commitment surface; `related:` stays context.