fn chunk_value(value: &str) -> Vec<&str>Expand description
Pure chunking split — no keychain I/O — so the boundary math is testable
without touching the real OS keychain. A token’s bytes are always ASCII
in practice (JWTs / opaque base64url strings), so splitting on byte
boundaries never lands mid-character; unwrap_or("") is a defensive
fallback only, not an expected path.