chain.id is a number instead of bigint

[topocount]

Check existing issues

• I checked there isn't already an issue for the bug I encountered.

Viem Version

2.9.27

Current Behavior

the chain id is typed as a number.

Expected Behavior

the chainId is specified as a uint256 and should therefore be a bigint. I understand that it's unlikely a developer will create a chainId large enough require uint256, but I'm mostly curious what the reasoning here is, or if there is a specification that I'm missing. handling the up and downcasts when passing chainIds around as params is not a huge deal in and of itself but if I'm creating a higher level sdk I'd like to understand how this is intended to be handled.

Steps To Reproduce

No response

Link to Minimal Reproducible Example

No response

Anything else?

No response

[jxom]

There is no reasoning for this.