fix(l2): override execution witness endpoint

[avilagaston9]

Motivation

In L2, every block is executed with a specific FeeConfig stored in the rollup_store, following the mapping block_number -> fee_config. Since the L1 RPC handler doesn’t have access to the rollup_store, it’s impossible to properly generate the execution witness.

Description

• Overrides the debug_executionWitness endpoint from the L2 to fetch each FeeConfig before generating the witnesses.

Closes None

[github-actions]

Lines of code report

Total lines added: 81
Total lines removed: 8
Total lines changed: 89

Detailed view

+---------------------------------------------------------+-------+------+
| File                                                    | Lines | Diff |
+---------------------------------------------------------+-------+------+
| ethrex/crates/l2/networking/rpc/l2/execution_witness.rs | 72    | +72  |
+---------------------------------------------------------+-------+------+
| ethrex/crates/l2/networking/rpc/l2/mod.rs               | 5     | +1   |
+---------------------------------------------------------+-------+------+
| ethrex/crates/l2/networking/rpc/rpc.rs                  | 213   | +8   |
+---------------------------------------------------------+-------+------+
| ethrex/crates/networking/rpc/debug/execution_witness.rs | 143   | -8   |
+---------------------------------------------------------+-------+------+

[avilagaston9]

This was unused

[Copilot]

Pull Request Overview

This PR overrides the debug_executionWitness endpoint in L2 to properly handle block-specific fee configurations. The L1 RPC handler lacks access to the rollup_store which maintains the block_number -> fee_config mapping required for accurate execution witness generation in L2.

Key Changes:

• Created a new L2-specific execution witness handler that fetches fee configurations from the rollup store
• Removed unused block_headers collection logic from the L1 execution witness handler
• Added endpoint override in the L2 RPC request mapper to intercept debug_executionWitness calls

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
crates/networking/rpc/debug/execution_witness.rs	Removed unused parent block header collection logic
crates/l2/networking/rpc/rpc.rs	Added override for debug_executionWitness to route to L2-specific handler
crates/l2/networking/rpc/l2/mod.rs	Exposed new execution_witness module
crates/l2/networking/rpc/l2/execution_witness.rs	Implemented L2-specific execution witness handler with fee config fetching

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