Cardano Updates

  Light wallets (Eternl, Lace, Yoroi) export HD-derived extended keys
  (PaymentExtendedKey — BIP32-Ed25519) which Hydra previously rejected.
  Convert extended keys to normal PaymentKey at load time so users can
  use wallet-exported key files directly with --cardano-signing-key and
  --cardano-verification-key without manual conversion.

  Instead of byte-slicing extended signing keys into normal keys (which
  produces wrong verification key hashes for BIP32-Ed25519), keep them
  native via a CardanoSigningKey sum type and signTxWith helper that
  delegates to the appropriate ShelleyWitnessSigningKey constructor.

Signed-off-by: Sasha Bogicevic <[email protected]>

The previous implementation of onClosedChainPartialFanoutTx computed the
  remaining UTxO by counting how many outputs were distributed and dropping
  that many from the front of the ordered full UTxO set (splitUTxOAt). This
  works for the current auto-chunking path, which always takes a contiguous
  prefix, but breaks for arbitrary user-selected subsets — the prerequisite
  for issue #2333.
Fix this by storing the expected remaining UTxO optimistically in
  ClosedState.pendingRemainingFanoutUTxO when emitNextFanoutStep posts a
  PartialFanoutTx. A new HeadPartialFanoutPrepared state change carries this
  value into the event log so it survives node restarts via replay.

Signed-off-by: Sasha Bogicevic <[email protected]>

  Introduce HydraNodeConfig record type and smart constructors
  (mkSoloConfig, mkTwoPartyConfigs, mkThreePartyConfigs) to replace
  positional arguments in withHydraNode, withHydraNodeCatchingUp, and
  withUnsyncedHydraNode. Update all call sites in Scenarios, EndToEndSpec,
  ChainObserverSpec, TUISpec, and Bench/EndToEnd accordingly.

Signed-off-by: Sasha Bogicevic <[email protected]>

Got all changes from the capi-10.21 branch here

Optimizations applied:
 * Single-pass serialization: each 'TxOut' is serialized once via
   @serialiseData . toBuiltinData@ and reused for both UTxO hash checks
   and accumulator scalar computation.
 * Combined CRS lookup: the reference input for the CRS is looked up once
   and decoded only when the membership check is actually reached.