Function format_robust_hold_report 

pub fn format_robust_hold_report(
    report: &RobustHoldReportV1,
    format: RobustHoldFormat,
    units: UnitSystem,
) -> String

Render a robust-hold report, identically on every surface (MBA-1349).

THE formatter: the native CLI prints what this returns. The command is native-only this train, but the sharing discipline is set up now so the WASM follow-up is a dispatch entry rather than a second copy of the format strings — the divergence the recoil CSV header suffered (MBA-1418) is exactly what that costs.

Returned strings are newline-terminated.