[Feat]: Root calls to revoke a registered name and evict a reservation queue #339

Component

Registration

Priority

P1

Summary

Governance can't take back a name or undo squatted reservations:

• Registered names: no call revokes one, whatever path issued it. The whitelist's revokeName only works until the name is registered.
• Reservation queues: an attester can fill them with candidates it controls, blocking a label even for verified persons and, by renewing weekly, indefinitely. Clearing its allowance stops new reservations, but existing ones stay until they expire.

Proposal

Two calls behind the governance gate (#238, #302):

• DotnsPopController.evictReservations(label) clears the label's whole queue and frees the label. A queue holds at most 64 entries, so one call is enough.
• Revoke a name: works like a forced release of a registered name or subname. The name returns to circulation, and its records and subnames are cleared the same way as on release ([Feat]: A reclaimed name keeps serving the previous owner's records and subnames #220). These questions are open:
  • Deposit: where the holder's escrow deposit goes (refunding the holder by default).
  • Redeem: whether the holder can redeem the name back within the redeem window, or revocation takes it away for good.
  • Gateway state: how _popIssued, the chat key and device-personhood links in DotnsPopResolver, pending claims and the pallet's AccountNames follow.

Acceptance criteria

• evictReservations clears a full queue in one call, and the label is reservable and registrable afterwards.
• A revoked name is available again like a released one
• Both calls revert for a signed caller and for Root outside the governance gate.
• The README describes both calls, including the change to its "cannot seize a name" guarantee.