fix(server): hub usage readings follow the credential and survive interrupted redeems

A hub credential replaced under the same file id now gets its own reading
instead of the old account's identity and bars. A redeem forgets the account's
reading on any exit once the account is found, interruption included, unless
the provider refused it with 429.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
54c8cf9457Yannic Charlon committed on 10/17/2026, 10:36:12 PMparent1006a51
2 files changedLine totals unavailable