fix(poll): harden lifecycle policy boundaries

README.md

@@ -87,6 +87,12 @@ and, when unavailable, the policy reason. Management clients can use the
 `GET /poll/polls/{poll_id}/transitions` endpoint to read the durable history
 instead of duplicating the matrix in their UI.
 
+Polls created through the v0.1.9 contract start in `draft` or `open`; later
+states are entered through the transition engine. Older archived rows may not
+contain the status from which they were archived. Their prior state cannot be
+inferred safely, so unarchive restores them to the least-permissive `draft`
+state and marks that legacy fallback explicitly in the audit metadata.
+
 ## Development Install
 
 ```bash