chore(protocol): refactor common logic of hardfork specific protocol code

[mablr]

This is expected to close #2933.

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[Copilot]

Pull Request Overview

This PR refactors common logic across hardfork-specific protocol code by extracting shared encoding/decoding functionality into centralized utilities. The refactoring eliminates code duplication while maintaining the same functional behavior.

• Introduces CommonL1BlockFields struct to handle shared encoding/decoding logic for Ecotone, Isthmus, and Interop hardforks
• Creates shared validation utilities for SystemConfig updates with common error handling patterns
• Consolidates duplicated validation logic across multiple update types (batcher, EIP1559, operator fee, unsafe block signer)

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
crates/protocol/protocol/src/info/mod.rs	Adds module declaration and export for new common utilities
crates/protocol/protocol/src/info/common.rs	Implements shared CommonL1BlockFields struct with encoding/decoding methods
crates/protocol/protocol/src/info/isthmus.rs	Refactors to use common encoding/decoding utilities, removes duplicated code
crates/protocol/protocol/src/info/interop.rs	Refactors to use common encoding/decoding utilities, removes duplicated code
crates/protocol/protocol/src/info/ecotone.rs	Refactors to use common encoding/decoding utilities, removes duplicated code
crates/protocol/genesis/src/updates/mod.rs	Adds module declaration for new common validation utilities
crates/protocol/genesis/src/updates/common.rs	Implements shared validation logic for SystemConfig updates
crates/protocol/genesis/src/updates/signer.rs	Refactors to use common validation utilities, removes duplicated validation code
crates/protocol/genesis/src/updates/operator_fee.rs	Refactors to use common validation utilities, removes duplicated validation code
crates/protocol/genesis/src/updates/eip1559.rs	Refactors to use common validation utilities, removes duplicated validation code
crates/protocol/genesis/src/updates/batcher.rs	Refactors to use common validation utilities, removes duplicated validation code

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[theochap]

Maybe you could have a method that encodes directly the common l1 block fields into bytes so that you don't need to use a buffer here

[theochap]

This is a great first step. I think we could go further and refactor each hardfork logic by building on top of the previous one: for instance Isthmus would would call Ecotone methods to encode all the fields before Isthmus. Then you would just need to add Isthmus specific logic. If a hardfork changes existing logic from the previous hardforks, you can refactor the method into a common helper that branches on the specific behavior that gets updated.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 83.9%. Comparing base (aa7e895) to head (0fca466).
⚠️ Report is 1 commits behind head on main.

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[mablr]

This is a great first step. I think we could go further and refactor each hardfork logic by building on top of the previous one: for instance Isthmus would would call Ecotone methods to encode all the fields before Isthmus. Then you would just need to add Isthmus specific logic. If a hardfork changes existing logic from the previous hardforks, you can refactor the method into a common helper that branches on the specific behavior that gets updated.

Thank you! I'll have a look to this in the next days, and would be happy to propose a follow-up PR 👍