Function integer_or 

pub fn integer_or(
    settings: &Settings,
    key: &str,
    default: i64,
    range: RangeInclusive<i64>,
) -> i64

An integer, clamped to what the setting can actually mean.

Out of range is treated exactly as unparseable: a subjectMax of 0 would block every commit forever from a config file, and one of 10_000 is not a limit. Both are mistakes, and both get the default plus a line saying so.