feat: route bounded hierarchy postbox copies

README.md

@@ -80,7 +80,17 @@ addresses, exact function-bound Postboxes, current IDM assignment access
 decisions, vacancy status, idempotent producer delivery, source-preserving
 message and attachment references, personal read/acknowledgement receipts,
 unified inbox projections, access evidence, an inbox route, and tenant
-administration.
+administration. Published template revisions can also opt into bounded linked
+copies through one explicit organization structure. Classification, producer,
+retention, stop, depth, target-template, and target-function gates are frozen
+at delivery time and exposed through delivery evidence and the routing dry-run
+API.
+
+Vacancy escalation is a separate attention policy. It creates no personal
+account grant: a durable route waits for its configured delay and then creates
+an independently readable copy in the next frozen function Postbox. The
+`govoplan.postbox.dispatch_routes` periodic Core worker drains due routes when
+Celery beat and a worker consuming the `postbox` queue are enabled.
 
 The persistence model reserves ciphertext manifests, wrapped keys, key epochs,
 expiry, and withdrawal state. The active profile remains `plaintext_v1`; the