//! Build the User-Agent string sent on every request.
use crateVERSION;
/// Build the User-Agent string. Format mirrors the sibling SDKs:
/// `audd-rust/<version> rust/<rustc-version> (<os>)`.
///
/// We deliberately don't read `RUSTC_VERSION` at runtime — `env!()`-baked at compile time is fine,
/// and we don't want to require any extra build infra. We resolve the rustc version at compile
/// time via the `RUSTC_VERSION` environment variable if set, falling back to "unknown".