Cardano Updates

Co-Authored-By: Claude Opus 4.6 <[email protected]>

This reverts commit 3fbdf40302bb81ca08abebfbfd384257578d50a8.

Prevents silent number coercion (float64) when unmarshaling arbitrary JSON.
Affects DrepMetadata.JSONMetadata, ProposalDetails.GovernanceDescription,
ProposalParameters.Parameters, ProposalMetadata.JSONMetadata,
ScriptJSON.JSON, and ScriptDatum.JSONValue.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

- TransactionPoolUpdates was hitting /txs/{hash}/delegations instead of
  /txs/{hash}/pool_updates (copy-paste bug)
- TransactionPoolRetirementCerts was returning []TransactionPoolCert
  instead of []TransactionPoolRetires, causing deserialization to
  silently produce zero-valued structs
- Update tests to use tx hashes that actually contain pool updates
  and retirements (from blockfrost-tests fixtures)
- Regenerate golden files with real data

Co-Authored-By: Claude Opus 4.6 <[email protected]>

Add tests for BlockTransactionsAll, BlockLatestTransactionsAll,
NetworkEras, PoolsExtended, ScriptJSON, ScriptCBOR, ScriptDatum,
ScriptDatumCBOR, AccountAddressesTotal, and AccountTransactions.
Deterministic endpoints use golden file comparison, dynamic endpoints
use null checks. Fixture IDs from blockfrost-tests repo.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

Add integration tests for all Conway governance endpoints (DReps and
Proposals) verified against mainnet.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

The push trigger on feat/test/docs/ref branches caused duplicate CI
runs when a PR is also open against master. Keep only push on master
and pull_request on master.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

No pools may be retiring at any given time, so an empty response
is valid and should not fail the test.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

The Quantity type (used for coins/assets in additionalUtxoSet) was
serializing as a JSON string ("1300000000") but the evaluate/utxos
endpoint expects a number (1300000000). Add MarshalJSON to output
numeric values. Update golden file with current evaluation result.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

Check URL and non-empty version instead of comparing against a golden
file with a hardcoded API version that goes stale on every release.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

The empty result was a transient condition (latest block had no txs),
not a code issue. Restore the original assertion.

Regenerate golden files for epoch parameters (Conway governance fields,
cost_models_raw), transaction content (treasury_donation), and
transaction UTXOs (consumed_by_tx). Fix BlockLatestTransactions test
that incorrectly failed on empty block results.

Add full Conway-era governance support (DReps + Proposals), missing
endpoints (NetworkEras, PoolsExtended, ScriptJSON/CBOR/Datum,
AccountAddressesTotal, AccountTransactions), paginated *All variants
for assets/blocks, and update existing structs with new fields from
the latest OpenAPI spec. Bump version to 0.4.0.

feat: add transaction cbor endpoint