v1.3.1

Live audio on iPhone works, contrary to what v1.3.0's release notes said. Investigating why it looked broken turned up three real defects, all fixed here.

The feed treated an ordinary manifest refresh as an encoder restart, because a live window's own segment numbering and timing advance on every update. Each false restart stranded its entire encoded ring instead of reclaiming it, so the ring grew without bound over a session, tens of megabytes an hour on a phone. A muted <video> element's own state was written back into the player's volume control on every change, which could re-enter itself and pin the audio gain at zero while the control bar still showed full volume. On a touchscreen the volume slider applies whatever value a tap lands on, with no drag required, over a range about 35 by 3 pixels; it is now hidden wherever the pointer is not a mouse, and level lives on the hardware buttons there instead.

A media session that fails with SRC_NOT_SUPPORTED, the "media could not be loaded" error with no recovery, is now caught and reloaded within about 30 seconds instead of being left dead. What raises that error in the first place is not established.

One failure stays entirely outside this player's reach: a Safari content process can lose all audio output while every API it exposes, Web Audio and a plain <audio> element alike, keeps reporting success. Nothing on the page can detect or repair it; only quitting Safari does. See docs/IOS-SAFARI.md for the measurements behind both open items.