poc-live — iowire multi-host studio POC

• /join.html?token=…&name=… — join the LiveKit room (camera+mic)
• /hls/program/ — watch the composited program (MediaMTX HLS player)
• /webrtc/program/ — same, low-latency WebRTC (WHEP) player

Temporary POC host. Tear down: terminate i-08728d93f0e93f47a, release EIP, delete DNS.