fix(configs): read the extraConfig block of a shelley genesis - #797

What?

This PR adds an injection module that reads the extraConfig block of a shelley genesis file. For each field in the file, it picks between the new injected value and the old top level value. It uses whichever holds entries (injected or top level) and refuses if both do. The shelley parser uses it for the three fields that can appear in extraConfig: initial funds, stake pools, and stake credentials.

The PR also has Pool entries now parse under the poolId and accountAddress names, which are the ledger's current names for those fields (as well as still parsing the old publicKey and rewardAccount).

Why?

cardano-cli 11.2.0.0 changed the format of the generated genesis file. It now has initial funds, pools, credentials, delegations, and initial DReps under extraConfig in the shelley and conway files and leaves the old top level fields empty (changelog at the tag, marked breaking). pallas-configs reads only the top level and not the changed injected fields, so pallas parses a genesis written by current tooling without error, reads it as empty, and so yields a chain that has no funds and no pools.

The published Musashi shelley genesis is a file generated by the new tool (pinned copy, blake2b-256 735d3f9f1f79066ead4ef7df4ac7e6ed25e8d78b7b9c7e5ec5ee1b88476e1c3f, which is the ShelleyGenesisHash its config.json declares). All 30000000900000000 lovelace of its supply is under extraConfig, its byron genesis has no funds at all and pallas main parses it to yield zero utxos.

Testing done

Added tests. One loads that Musashi genesis, asserts its top level initialFunds is empty, and asserts the utxos computed from it add up to the full 30000000900000000 lovelace. The rest use a fixture generated by cardano-cli 11.2.2.0 genesis create-testnet-data and committed exactly as the tool wrote it. The injection-vs-top-level resolve rule is tested case by case, each of the three shelley fields is tested end to end including its refusal, and the four existing fixtures still parse to what they did before.

$ cargo test -p pallas-configs
running 43 tests
test result: ok. 43 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 1.05s

Notes

Three places this change deliberately differs from how the ledger resolves the same fields:

• A file injection, one that names a separate file and its hash instead of holding the data inline, is refused rather than read. This would've caused a larger change that would require the parser to need to know about the path to the file that seemed unnecessary to add to this PR.
• A pool entry that carries both the old and the new name for a field is accepted, preferring the new one, which is what the ledger does. A serde alias would have rejected it as a duplicate field.

Summary by CodeRabbit

• New Features
  • Added support for Shelley genesis data supplied through extraConfig, including initial funds, stake pools, and stake credentials.
  • Added support for loading injected configuration from external files relative to the genesis file.
  • Added validation for conflicting, incomplete, unsupported, or incorrectly hashed injection sources.
• Documentation
  • Documented configuration injection support.
• Tests
  • Added coverage for embedded and file-based injections, validation, and representative Shelley genesis configurations.