bug: Negative timestamp and gasLimit wrap to huge uint64 values in MakeHeader

[Aboudjem]

Bug Description

In rpc/types/utils.go, MakeHeader casts potentially negative values to uint64:

Time: uint64(header.Time.UTC().Unix()),

For pre-epoch timestamps, Unix() returns negative int64 which wraps to huge uint64 values.

Impact

Edge cases (clock skew, test chains, pre-epoch blocks) produce incorrect timestamps in eth_getBlockByNumber responses.

Proposed Fix

Clamp negative values to 0 before uint64 cast.

[linear]

EVM-444

[swift1337]

Closing for being a low-effort AI submission.