fix(people-lists): track per-mutation delete outcomes #6696

Problem

UserListPeopleScreen currently infers the delete it issued from the bloc-wide PeopleListsStatus.failure value. That can misreport a delete outcome when another people-list mutation has already pinned the global status to failure while this delete settles successfully.

The current PR (#6667) fixes teardown-dropped deletes by recording the owner and checking that the mutation resolved in the same owner/enabled state. The remaining ambiguity is per-mutation result status: once the delete mutation leaves pendingMutations, the screen cannot tell whether the delete itself failed or whether the global status belongs to a different in-flight/recent mutation.

Expected

Delete feedback should be driven by this delete mutation own completion result, not the global people-lists bloc status.

Notes

Avoid using list presence as the only signal. A pre-delete repository emission can arrive mid-flight and temporarily put the list back before the repository successful deletion cache emission lands, so list presence alone can misclassify a successful delete as failed.