v2.12.0

TinyIce 2.12.0

Added: browser video broadcasting. Go Live now offers microphone,
camera, screen share or a local video file, publishing audio plus H.264
video over one WebRTC peer connection. Video is republished on the
mount's /video sibling in the shape the RTMP ingest produces, so HLS,
the player and WHEP pick it up unchanged.

The ingest codec set is restricted to Opus and H.264 deliberately: every
video consumer here is H.264 and there is no video transcoder, so a
browser that cannot encode H.264 fails negotiation rather than sending a
format nothing could play.

Verified end to end with a real browser publishing into a live server:
both mounts created, and a listener capture of the video mount decoded
as H.264 Baseline, 335 frames, zero decode errors.

Full notes in CHANGELOG.md.