/// Which OS-level name resolution model we're simulating.
///
/// MVP scope is Linux only. macOS resolution goes through mDNSResponder /
/// `scutil --dns` and largely ignores resolv.conf — different enough that
/// it needs its own module later, not a branch bolted onto this one.
/// Windows (DNS Client service, LLMNR, NetBIOS) is further out still.
/// Deliberately not building either now — see manifesto: no cathedral.
/// Currently always returns [`Platform::Linux`] — see [`Platform`] for why
/// the other variants don't exist yet.
/// Well-known config file paths this crate's parsers read from.