7.47.0 - 3D on visionOS, Atmos activator on HDMI again

Added

• 3D on visionOS (AE#812, thanks @williamliu0516). MV-HEVC keeps its second view (the muxer marks the stream AV_DISPOSITION_MULTILAYER, so movenc writes lhvC, and the hvcC canonicalization keeps the 3D reference displays SEI 176 that AVFoundation needs to decode both views). Side-by-side and over-under HEVC get Apple's vexu { eyes, pack } in the init segment and play as stereo without a re-encode. Both declare REQ-VIDEO-LAYOUT="CH-STEREO" (EXT-X-VERSION 12). New LoadOptions.stereoPresentation (.automatic, .sideBySide, .overUnder, .mono); aetherctl serve --stereo auto|mono|sbs|ou. Packed H.264 stays 2D (AVPlayer refuses it over HLS, -12927).

Changed

• AtmosOutputActivator runs for TrueHD Atmos only. A DTS:X track rendered to APAC no longer loops the silent Dolby Atmos stream, so the receiver does not show Dolby Atmos for a DTS programme.
• Object size, snap and zone masks exist only in the TrueHDReferenceRender measurement build. The shipped TrueHD path already rendered every object as a point; that code is now compiled out of it. No change to what a shipped build plays.

Fixed

• The Atmos activator plays on HDMI again (regression from 7.45.0, AE#834). It compared the route against "HDMI" while AVAudioSession.Port.HDMI is "HDMIOutput", so it refused every HDMI route and receivers that need it stopped showing Dolby Atmos for TrueHD Atmos rendered to APAC.
• A resume from pause no longer publishes one tick of .rebuffering (Sodalite#168). The brief AVPlayerWaitingWhileEvaluatingBufferingRateReason wait on every resume no longer counts as a rebuffer on the native and audio-only hosts; a real shortage (toMinimizeStalls) still does.
• A software live join starts picture and sound together (AE#844, thanks @l984-451). The join now starts on the first keyframe instead of arming the clock on the first audio, which left 1.3 to 2.9 s of sound over a black screen on every join (Apple TV 4K, Plex Live TV). With a DVR ring the cursor waits at most 3 s for the lead the unmoved start had; a stream that flags no keyframe keeps its old start.

Docs

• Plozz added to the used-by list.

Full changelog: CHANGELOG.md · 7.46.0...7.47.0