//! Publisher origin — local client or upstream SFU relay connection.
/// Whether this client represents a direct peer or an upstream SFU relay.
///
/// `Local` is the default — a direct WebRTC peer connection. `RelayFromSfu`
/// is set by the application after ICE/DTLS completes on the edge-to-edge
/// relay connection; the string is an opaque upstream edge identifier
/// (typically URL or region ID) used for logging and diagnostics.
///
/// # Call order
///
/// Call [`Client::set_origin`][crate::Client::set_origin] **before**
/// [`Registry::insert`][crate::Registry::insert]. The insert path reads
/// `is_relay()` to decide whether to register the peer with the
/// dominant-speaker detector.