PTP timing support for AirPlay 2

[bradkeifer]

Adds support for PTP timing to be used for AirPlay 2 players.
AirPlay 2 implementation of Shairport Sync only supports PTP timing, and does not work with NTP timing.
Samsung devices appear to only support PTP timing for their AirPlay 2 implementation also.
PTP timing with AirPlay 2 is also a prerequisite to future implementation of buffer RTP and hi-res audio support into the AirPlay 2 provider.

[bradkeifer]

Over to you @MarvinSchenkel for the python changes.

[dantelope]

Hi @bradkeifer @MarvinSchenkel — happy to help test on Samsung Frame whenever this is closer to a testable state.

Test environment:

• Samsung Frame TV (post-2018, AirPlay 2 confirmed working from native iOS/macOS clients)
• HA + Music Assistant on Linux x86_64 (Beelink, HA OS amd64)
• Frame currently auto-discovered by MA's AirPlay 2 provider and flagged via BROKEN_AIRPLAY_MODELS — silent playback as expected
• A couple of working AirPlay 2 targets (Mac, Kitchen Display hardware via Google Cast) for sync-group comparison

I can verify: basic playback (does audio come out), volume control, sync grouping, and behavior with BROKEN_AIRPLAY_MODELS bypassed. Can capture mDNS/RTSP packet traces and MA logs if useful.

Two questions:

1. Is there a branch I can try now, or should I wait for the Python side?
2. Will airptpd run as a sidecar alongside cliap2, or replace AirPlay 2 entirely in that path?

Thanks for the work on this — Samsung Frame in particular is a common-enough device that even a "known issue resolved" landing would be a big quality-of-life win.