fix(inspector): clamp negative EIP-3155 refund to zero

[cuiweixie]

Summary

• Clamp refunded with .max(0) before casting to u64 in the EIP-3155 tracer.
• A negative i64 refund previously wrapped to a huge unsigned value in the JSON output; this matches the existing state_gas clamp.

Test plan

• cargo nextest run -p revm-inspector
• cargo clippy --workspace --all-targets --all-features

[codspeed-hq]

Merging this PR will not alter performance

✅ 218 untouched benchmarks
⏩ 9 skipped benchmarks¹

---

_{Comparing cuiweixie:fix/eip3155-clamp-negative-refund (c3cb859) with main (8ca4052)}

Footnotes

1. 9 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩