docs(readme): note AV1 DV Profile 10.0 wrong colours on software decode

dav1d / libavcodec cannot decode the proprietary DV colour space, so DV
P10.0 (DV-only, no fallback base layer) renders with wrong colours on the
SW path. P10.1 / P10.4 are unaffected (HDR10 / HLG base layer). P10.0 needs
the native AVPlayer path with HW AV1 decode. Documented as a known
limitation per DrHurt's findings in issue #4.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: superuser404notfound

README.md

@@ -378,6 +378,7 @@ Things that work today but have a documented edge case, or are deferred behind a
 - **HDMI route reports ch=2 → multichannel plays as stereo.** When the sink reports a 2-channel audio route (`AVAudioSession.outputNumberOfChannels == 2`), all non-Atmos multichannel material downmixes to stereo. This is a sink-side issue (some AVRs cache HDMI EDID incorrectly after standby). Power-cycling the sink restores the correct route. Atmos passthrough still works on these routes because EAC3+JOC ships as MAT 2.0 over a 2-channel carrier.
 - **Live MPEG-TS sliding-window segment eviction is not yet implemented.** `LoadOptions.isLive` enables the scaffold (no-op seek, `@Published isLive`), but long-running live sessions on the native AVPlayer path accumulate cached segments. Live VOD playback works; multi-hour IPTV / broadcaster feeds will grow memory until the source ends.
 - **AV1 on Apple TV is software-decoded.** No current Apple TV chip ships HW AV1. The `SoftwarePlaybackHost` + dav1d path handles it, but CPU use is meaningfully higher than HW HEVC. On iOS 17+ / macOS 14+ AV1 routes through Apple's HW pipeline transparently. Future Apple TV chips with HW AV1 will be picked up automatically by `VTCapabilityProbe`.
+- **AV1 Dolby Vision Profile 10.0 has wrong colours when software-decoded.** dav1d / libavcodec cannot decode the proprietary DV colour space, so a Profile 10.0 source (DV-only, no fallback base layer) renders with incorrect colours on the SW path. Profiles 10.1 and 10.4 are unaffected because they carry an HDR10 / HLG base layer that the decoder reads correctly. Profile 10.0 only renders correctly through the native AVPlayer path on hosts with HW AV1 decode (M3+ Mac, iPhone 15 Pro+, future Apple TV chips); on software-decode hosts (all current Apple TVs) it is a known colour limitation.
 
 ## Stability and versioning