Fix stake address deposit repayment timing

[sandtreader]

Deposit calculations was until recently valid until epoch 215 (or beyond, because rewards breaks there) but some recent change now fails it at epoch 210:

2025-10-27T10:01:37.419398Z  INFO acropolis_module_accounts_state::state: 11 retiring SPOs, total refunds 5500000000
2025-10-27T10:01:37.419411Z  INFO acropolis_module_accounts_state::state: 11 deregistered stake addresses, total refunds 22000000
2025-10-27T10:01:37.419421Z ERROR acropolis_module_accounts_state::verifier: Verification mismatch: deposits for epoch=210 calculated=533848000000 desired=533870000000 difference=22000000

My guess this change was made to improve @whankinsiv's SPDD check, so perhaps our deposits check is wrong - either way they seem to be incompatible.

It also triggers a rewards divergence earlier than before (211 instead of 213) which then throws out reserves and hence all calculations from then on):

2025-10-27T10:01:55.465682Z ERROR acropolis_module_accounts_state::verifier: Missing reward: SPO c63dab6d780a74cbae2a27696c9723f55b3092b2bd001256df03827f account 0160fffc9996829dcfcedff505040d72b4eb73baae5008433ffbcc36 Leader 715140393
2025-10-27T10:01:55.468854Z ERROR acropolis_module_accounts_state::verifier: Rewards verification: errors=1 epoch=211
...
2025-10-27T10:01:55.484537Z ERROR acropolis_module_accounts_state::verifier: Verification mismatch: reserves for epoch=213 calculated=13247093913493852 desired=13247093198353459 difference=-715140393
2025-10-27T10:01:55.484541Z ERROR acropolis_module_accounts_state::verifier: Verification mismatch: deposits for epoch=213 calculated=651542000000 desired=651738000000 difference=196000000

[whankinsiv]

Hi @sandtreader. I intentionally left out any changes to rewards / deposit logic in #261 out of concern that it may incorrectly alter the logic you had designed. During my SPDD validation testing I did notice that the Verifier was producing errors as early as epoch 209.

[sandtreader]

OK, this is on me then! Investigating..