Admin-gated /admin/accounts tool to administer individual accounts via the SERVICE-scoped admin endpoints (sibling Treasury API tranche):
Rename an account (display name).
Change owner (by UUID or player name) — surfaced guard for the one-PERSONAL-per-player rule.
Archive / unarchive an account.
lib/treasury.ts: adminRenameAccount, adminChangeAccountOwner, adminArchiveAccount, adminUnarchiveAccount.
lib/actions/admin-accounts.ts: admin-gated, each audited (explorer_audit, target_type account).
UI: search an account (id/name/owner via existing account DAL), show its current state (type/owner/archived/balance), and the actions; confirm for archive/owner-change.
Reuses the admin gate + lib/treasury.ts client from PAR-209.