Function filing_status_tag 

pub fn filing_status_tag(fs: FilingStatus) -> &'static str

Stable display tag for FilingStatus (lowercase, matches the CLI value-enum strings).

Values: “single” | “mfj” | “mfs” | “hoh” | “qss”. These mirror the FilingStatusArg ValueEnum strings accepted by --filing-status, so the tax-profile --show output is round-trip-parseable via the same flag.