Cardano Updates

Also reduce a diff in the test code

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

  Replace the hardcoded numToDistribute = totalUTxO - 1 in the partial
  fanout benchmarks with a binary search that finds the largest chunk
  actually fitting within both the tx size and execution budget, mirroring
  findFittingFanoutTx in the real node. The Remaining column in the output
  table now carries meaningful information instead of always showing 1.

  Also add ContestationDeadlineOutsideTimeHorizon to the PostTxError
  oneOf in api.yaml, which was defined in Chain.hs but missing from the
  schema, causing ServerOutputSpec to fail.

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

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

  computeFinalPartialFanOutCost was capped at 7 (fanoutChunkSize), hiding
  the real tx-size limit for the terminal fanout step. Now it sweeps a wide
  range and searches for the actual maximum, using a single preceding output
  as minimal setup to reach FanoutProgress.

  computePartialFanOutMixedCost also dropped its fanoutChunkSize cap and
  now distributes all-but-one outputs, consistent with the nominal benchmark.
  The stale description mentioning fanoutChunkSize is corrected accordingly.

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

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

  fanoutChunkSize and fanoutOutputThreshold are now defined once in
  Test.Hydra.Tx.Fixture and imported wherever needed, removing the
  per-file duplicates.

  prepareTxToPost gains explicit FanoutTx/FinalPartialFanoutTx branches
  (error) so GHC's exhaustiveness checker catches any future unhandled
  constructor, instead of silently falling through a wildcard.

  The two deadline-slot conversions in mkChain.postTx now throw
  FailedToConstructFanoutTx (a PostTxError Tx) instead of userError,
  so the exception is caught by Node.hs's PostTxError handler rather
  than propagating uncaught and crashing the node.

  HeadLogic no longer uses fanoutChunkSize or fanoutOutputThreshold to decide
  which tx type to emit. For a fresh fanout it always emits FanoutTx; for an
  in-progress fanout it always emits FinalPartialFanoutTx. Handlers now owns the
  sizing decision: it tries the preferred tx first, then falls back to
  PartialFanoutTx with a decreasing chunk size (starting at N-1) until one fits
  within the execution budget, using a single shared findFittingFanoutTx helper.

  PartialFanoutTx is removed from PostChainTx — it is now an internal Handlers
  detail, never emitted by HeadLogic. fanoutChunkSize and fanoutOutputThreshold
  are removed from KZGTrustedSetup and all call sites.

  The SQLite event store accumulates events from all head lifecycles without
  rotation. On restart, `aggregate` replays every persisted StateChanged event
  but unlike the live `handleChainInput` path, never checked that an event's
  headId matched the current state — so a HeadClosed or HeadFannedOut event
  from a previous head could silently drive an unrelated Open/Closed head into
  the wrong state.

  Fix: add `eventHeadId` and `headIdOf` helpers and a single pre-check at the
  top of `aggregate`. Any event whose headId does not match the current state's
  headId is silently dropped. Events that carry no headId are always applied,
  preserving existing behaviour for TransactionReceived, ChainRolledBack, etc.

  Regression tests cover the two critical cross-phase transitions:
  Open→Closed via HeadClosed and Closed→Idle via HeadFannedOut from a
  mismatched head.

Also reduce a diff in the test code

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

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

  Replace the hardcoded numToDistribute = totalUTxO - 1 in the partial
  fanout benchmarks with a binary search that finds the largest chunk
  actually fitting within both the tx size and execution budget, mirroring
  findFittingFanoutTx in the real node. The Remaining column in the output
  table now carries meaningful information instead of always showing 1.

  Also add ContestationDeadlineOutsideTimeHorizon to the PostTxError
  oneOf in api.yaml, which was defined in Chain.hs but missing from the
  schema, causing ServerOutputSpec to fail.

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

  computeFinalPartialFanOutCost was capped at 7 (fanoutChunkSize), hiding
  the real tx-size limit for the terminal fanout step. Now it sweeps a wide
  range and searches for the actual maximum, using a single preceding output
  as minimal setup to reach FanoutProgress.

  computePartialFanOutMixedCost also dropped its fanoutChunkSize cap and
  now distributes all-but-one outputs, consistent with the nominal benchmark.
  The stale description mentioning fanoutChunkSize is corrected accordingly.

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

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

  HeadLogic no longer uses fanoutChunkSize or fanoutOutputThreshold to decide
  which tx type to emit. For a fresh fanout it always emits FanoutTx; for an
  in-progress fanout it always emits FinalPartialFanoutTx. Handlers now owns the
  sizing decision: it tries the preferred tx first, then falls back to
  PartialFanoutTx with a decreasing chunk size (starting at N-1) until one fits
  within the execution budget, using a single shared findFittingFanoutTx helper.

  PartialFanoutTx is removed from PostChainTx — it is now an internal Handlers
  detail, never emitted by HeadLogic. fanoutChunkSize and fanoutOutputThreshold
  are removed from KZGTrustedSetup and all call sites.