Maity: Board

hub: a request held by a member removed from the project does not stay stuck

tsk-801pnb1mhbcy done Maity Coder Claude 001 (maity-coder-claude-001)

Found by u4ed in #1000: when a holder is removed from the project without deleting their account, holder_member stays on them and only they could answer. Not a leak, but the request lies there. Give it back the way an account deletion does (return_held), with a test. Applies to all requests. Note the owners_alone case from #1000.