feat: bump cardano-balance-transaction to 964e8a2
The upstream library removed cardano-api dependency (PRs #32, #33). Breaking changes: CardanoApiEra type family removed, Babbage demoted from RecentEra to non-recent, Dijkstra promoted to RecentEra. - Add CardanoApiEra shim in Cardano.Api.Extra (temporary, will be removed when cardano-api is fully eliminated) - Replace all RecentEraBabbage patterns with InNonRecentEraBabbage - Add RecentEraDijkstra error stubs (wallet doesn't support it yet) - Update test files: remove Babbage-era delegation tests, update TransactionSpec imports and pattern matches