fix(anvil): preserve OP receipt fields in convert_to_anvil_receipt

[Syzygy106]

Motivation

I decided to help Foundry community and fix the following bug: #12345
Closes #12345

Solution

Anvil now preserves Optimism's L1 gas fields when forking

When running Anvil in fork mode against Optimism, receipt fields like l1Fee, l1GasPrice, and l1GasUsed were getting lost. These fields are Optimism-specific and don't exist in standard Ethereum receipts, so they didn't fit into Anvil's TransactionReceipt type.

The problem:
Anvil's ReceiptResponse was just a plain TransactionReceipt<TypedReceiptRpc>, which meant any extra JSON fields from the upstream node got silently dropped. Optimism stores its L1 gas data in an other map, but convert_to_anvil_receipt was throwing it away.

The fix:

• Changed ReceiptResponse to WithOtherFields<TransactionReceipt<TypedReceiptRpc>> so Anvil keeps unknown fields instead of discarding them
• Updated convert_to_anvil_receipt to preserve the other fields
• Added .inner access where needed (like in eth/api.rs)
• Unwrapped WithOtherFields when converting to Otterscan API types (to maintain API compatibility while preserving fields internally)
• Made sure locally-built receipts also use WithOtherFields with an empty map for consistency
• Added a test that creates a synthetic Optimism receipt and verifies all L1 fields survive the conversion

Why it works:
WithOtherFields<T> from alloy-serde does exactly what we need—it preserves unknown JSON keys without touching the core schema. Now Anvil keeps all of Optimism's extra receipt data intact. Regular Ethereum receipts without these fields still work exactly as before.

Notes for reviewers:

1. I didn't add documentation since this fix brings the behavior in line with what users would naturally expect. If you think docs are needed somewhere, happy to add them—just let me know where.

2. I changed the response type and updated all the places where it's unpacked. I've run the tests and builds, and everything looks good, but I'd appreciate another set of eyes on the downstream logic—just in case I missed something that might be affected by the type change.

PR Checklist

• Added Tests
• Added Documentation
• Breaking changes

[mattsse]

great

smol nits

[mattsse]

great

[mattsse]

@Syzygy106 just needs cargo +nightly fmt --all

[Syzygy106]

@Syzygy106 just needs cargo +nightly fmt --all

got it