//! Live capture from the fixed three-camera rig.
//!
//! Pipeline role (PLAN.md, "Pipeline per frame" — capture):
//!
//! * Kinect v2 RGB + depth via `kinect-one`
//! * two side webcams via `nokhwa`
//! * timestamp alignment and frame sync across the three asynchronous
//!   sensors (tolerate ~1 frame of skew)
//!
//! Camera extrinsics are known exactly from the existing offline
//! calibration; the camera overlap regions are checked at runtime as a
//! sanity check.
//!
//! Live capture must present the same rig-frame interface as `replay`, so
//! that live and recorded/synthetic input are interchangeable downstream.