UserByMCUUID now resolves only live accounts: claim, menu, wake
authorization, op-login vouch and the QR link-status poll treat a
disabled or soft-deleted link holder exactly like an unlinked UUID
instead of a retired identity. VerifyLinkCode lets a soft-deleted
link be taken over by a fresh in-game code (the deleted account is
gone, e.g. a migrated source), while a disabled holder still 409s so
the lockout is not bypassable; failed attempts still do not consume
the code. Fake repo and pgint coverage pin both branches.