Constant DEFAULT_MIN_SAVINGS 

pub const DEFAULT_MIN_SAVINGS: usize = 128; // 128usize

Minimum byte savings (original.len() - normalized.len()) for project_messages to accept a normalization candidate — SPEC.md TR-4’s “savings floor” knob, mirrored as ReductionPolicy::terminal_output_min_savings. Exposed here as the documented default; the policy field is what callers actually tune.