Old account runs /felis migrate in-game to open a migration, proves control via a
fresh web step-up (passkey forced when enrolled, else email-OTP), names the target
and mints a one-time code. The target redeems it while authenticated AS that target:
in one transaction the source's owned servers re-point to the target and the source
is retired (sessions revoked, disabled, soft-deleted), which also spends the code so
it cannot be replayed. Only server ownership moves; the mc_uuid link and web
credentials stay with the source, so migrate is not a credential-theft primitive.
- 0015 migration: account_migrations state machine (initiated -> confirmed ->
code_issued -> redeemed), one live migration per source
- Repo/PGRepo: Start/ForSource/Confirm/IssueCode/Redeem
- 8 routes (1 internal /felis side, 7 web) with openapi parity
- passkey step-up runs the same clone-signal (sign-count) check as the login door
- code bound to the named target at issue and at redeem
Quota is grandfathered at redeem: no per-target quota re-check when servers move.
