Server: reads all 3 cameras from Isaac Sim SHM, encodes JPEG
(head Q85, wrists Q70), sends with 1-byte camera ID prefix.
Head at ~10fps, wrist cameras at ~5fps for bandwidth control.
Godot: teleop_client parses camera ID byte and emits per-camera
signals. Three webcam quads arranged in a row (left|head|right)
in front of the user in AR mode.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>