Migrate to EraBasedProtocolParametersUpdate

[Jimbo4350]

Changelog

- description: |
    Migrate cardano-cli to the cardano-api removal of `ProtocolParametersUpdate`
    in favour of `EraBasedProtocolParametersUpdate era`. JSON output of
    `friendlyProtocolParametersUpdate` keeps the original flat shape and key
    names; cost models and Conway-only governance fields are not emitted (parity
    with prior behaviour) and can be surfaced in a follow-up.
# uncomment types applicable to the change:
  type:
   - compatible     # the API has changed but is non-breaking
   - refactoring    # QoL changes

Context

Companion to cardano-api PR IntersectMBO/cardano-api#1103 (branch jordan/remove-ProtocolParametersUpdate), which removes the deprecated ProtocolParametersUpdate type. This PR adapts cardano-cli to the era-indexed replacement and drops a redundant round-trip in the Shelley-to-Babbage governance flow.

This PR is draft because it depends on the cardano-api PR landing first — CI here will only go green once the api change is merged and pinned in cabal.project. Locally I built it against the cardano-api worktree.

Three files touched:

• cardano-cli/src/Cardano/CLI/Read.hs — readTxUpdateProposal now uses shelleyToBabbageEraConstraints w $ ... to bring IsShelleyBasedEra era into scope (required by the HasTextEnvelope instance on the now era-indexed UpdateProposal era). The exposed signature is unchanged, which avoids cascading constraints into callers.
• cardano-cli/src/Cardano/CLI/Compatible/Json/Friendly.hs — friendlyProtocolParametersUpdate rewritten to take EraBasedProtocolParametersUpdate era and dispatch on the GADT, with one helper per sub-record (commonPairs, deprecatedAfterMaryPairs, deprecatedAfterBabbagePairs, shelleyToAlonzoPairs, alonzoOnwardsPairs, introducedInBabbagePairs). JSON output remains flat with the original key names preserved ("max block body size", "min UTxO value", etc.). Ledger-side coercions: Ledger.fromCompact for CoinPerByte, Ledger.unboundRational for UnitInterval/NonNegativeInterval, fromAlonzoExUnits and fromAlonzoPrices to map back to the API types whose ToJSON instances match the prior output shape.
• cardano-cli/src/Cardano/CLI/Compatible/Governance/Run.hs — drop the redundant createEraBasedProtocolParamUpdate sbe ... |> fromLedgerPParamsUpdate sbe ... round-trip in shelleyToBabbageProtocolParametersUpdate. The new makeShelleyUpdateProposal takes EraBasedProtocolParametersUpdate era directly. The other createEraBasedProtocolParamUpdate call in conwayOnwardsProtocolParametersUpdate is genuine (feeds the result into Ledger.UpdatePParams) and is left intact.

Deliberate omissions in JSON output

To preserve the prior flat output, two groups of fields present in the new type are not emitted:

• alCostModels from AlonzoOnwardsPParams
• All of IntroducedInConwayPParams (voting thresholds, governance deposits, committee parameters, etc.)

Neither was emitted by the old friendlyProtocolParametersUpdate either. They can be added under new keys in a follow-up PR if we want Conway-era updates to fully round-trip in the friendly view.

How to trust this PR

• Build against the companion cardano-api branch by adding to cabal.project.local:

  packages: <path-to-cardano-api>/cardano-api
  

  then cabal build cardano-cli -j4. The library, cardano-cli-test, and cardano-cli-golden all link cleanly.
• Confirm the JSON shape parity by inspecting friendlyProtocolParametersUpdate against the original (the flat key list is preserved verbatim — pull diff and look at the commonPairs / *Pairs helpers vs. the original case branches).
• The Read.hs change is mechanical: existing callers see the same type signature.

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated. See Running tests for more details
• Self-reviewed the diff