One-Way Audio

// WRONG — the bridge is unreferenced the moment attach() returns.
// Once GC runs, downlink stops and the caller hears silence.
await voice.audioBridge.attach(sid, {
  onUplink: (frame, tsUs) => asr.push(frame),
});

// RIGHT — hold the handle for the life of the call, close on hangup.
const bridge = await voice.audioBridge.attach(sid, {
  onUplink: (frame, tsUs) => asr.push(frame),
});
calls.set(sid, bridge);            // keep a live reference

// ...later, when the call ends:
bridge.publishDownlink(lastFrame, Date.now() * 1000);
await bridge.close();              // deterministic teardown
calls.delete(sid);