Cardano Updates

Bumps [golang.org/x/crypto](https://github.com/golang/crypto) from 0.52.0 to 0.53.0.
- [Commits](https://github.com/golang/crypto/compare/v0.52.0...v0.53.0)

---
updated-dependencies:
- dependency-name: golang.org/x/crypto
  dependency-version: 0.53.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Signed-off-by: Chris Gianelloni <[email protected]>

Implement the Shelley POOLREAP transition embedded in the Conway EPOCH rule.
At each epoch boundary, pools whose retirement epoch is the new epoch have
their deposit refunded to the pool's registered, active reward account, or
added to the treasury when that account is missing or inactive.

- GetPoolsRetiringAtEpoch metadata query (sqlite/postgres/mysql) returns the
  retiring pools with the reward account and deposit from their active
  registration, excluding retirements cancelled by a later re-registration
  (same-slot disambiguation matches GetActivePoolKeyHashesAtSlot).
- applyPoolRetirements runs before governance enactment so treasury-bound
  deposits are visible to enacted withdrawals; reuses the governance
  credit-or-treasury helpers (now exported) for consistent accounting.
- Active pool membership stays query-derived; retirement rows remain so the
  slot-keyed reward and network_state writes are reverted on rollback and
  re-application is deterministic.
- Ordering invariant test updated to pin POOLREAP between pparam updates and
  governance enactment. Adds query, refund, treasury, and rollback tests.
- Updates DATABASE.md and ARCHITECTURE.md.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Signed-off-by: Chris Guiney <[email protected]>