pub fn resolve_flag(args: &[String], flag: &str) -> Option<String>Expand description
Resolve a flag value from CLI args + its NMBRS_-prefixed
env var. Returns None if neither is set. Exits with
status 2 if BOTH are set — configuration conflict; we
refuse to silently disambiguate.
Per SRD-04 the env-var name is automatically derived from
the flag name (--foo-bar → NMBRS_FOO_BAR).