[Bug] Floating point arithmetic in base fee calculation

[qj0r9j0vc2]

Description

Base fee calculation uses floating point arithmetic which can cause precision loss with large values.

Location

cipherbft/crates/rpc/src/eth/api.rs

Lines 918 to 923 in 1140ac3

	let increase = (last_base_fee as f64 * 0.125 * (last_ratio - 0.5) * 2.0) as u128;
	last_base_fee.saturating_add(increase)
	} else {
	// Block was less than 50% full, decrease base fee
	let decrease = (last_base_fee as f64 * 0.125 * (0.5 - last_ratio) * 2.0) as u128;
	last_base_fee.saturating_sub(decrease)

Severity

Medium - May cause fee calculation inconsistencies.