✨ verifyBlockHash + toShortHeader

[0xClandestine]

Description

Adds minimal block header utilities for state proofs + light client implementations.

• Added BlockHashLib.verifyBlockHash(blockHeader, blockNumber)
  Validates RLP-encoded headers against BlockHashLib.blockHash(blockNumber).

• Added BlockHashLib.toShortHeader(blockHeader):
  Efficiently extracts relevant fields from RLP-encoded block headers for MPT proof verification, without full RLP-decoding.

/// @dev Ethereum block header fields relevent to historical MPT proofs.
struct ShortHeader {
    bytes32 parentHash;
    bytes32 stateRoot;
    bytes32 transactionsRoot;
    bytes32 receiptsRoot;
    bytes32[8] logsBloom;
}

Checklist

Ensure you completed all of the steps below before submitting your pull request:

• Ran forge fmt?
• Ran forge test?

Pull requests with an incomplete checklist will be thrown out.

[0xClandestine]

Fork tests are preferred, not sure how you handle them though.

[0xClandestine]

Need to bump forge-std to support vm.getRawBlockHeader.

[Vectorized]

i think we’ll just fake it for now.

when we are really free, we can add a CI that does fork testing.

[0xClandestine]

Is xor more efficient here than iszero + eq?

[Vectorized]

not for here, i think.

[0xClandestine]

#1449

[0xClandestine]

anything else needed on this?