Add DPL2 surround output for tvOS

[joeblack2k]

Summary

• enable Dolphin’s Dolby Pro Logic II decoder for tvOS
• send decoded PCM as MPEG 5.1 in L R C LFE Ls Rs order
• fall back to MPEG 5.0 when the route rejects an LFE channel, then stereo
• make the isolated dependency patch stack reproducibly idempotent

Tests

• python3 tests/test_tvos_contract.py
• repeated ./scripts/prepare-tvos-dependencies.sh
• tvOS compile through CoreAudioSoundStream.cpp, libaudiocommon.a, and libmoderngekko.a
• bash -n scripts/prepare-tvos-dependencies.sh
• git diff --check

[joeblack2k]

Physical Woonkamer validation (HDMI route): [SunPad audio] RemoteIO initialized at 48000 Hz, channels=6, DPL2=1. The runtime created and loaded the GMSE01 module. This proves six-channel DPL2 decode/output initialization on the Apple TV; speaker-by-speaker acoustic verification was not performed.

[chrissotraidis]

Thank you, Jeroen — the six-channel DPL2 implementation and safe stereo fallback are now incorporated in merged PR #42 and the published Preview 12 release. Your physical six-channel initialization evidence is recorded and your commits are attributed to your GitHub account. We are deliberately keeping audible speaker-by-speaker channel placement as an exact-artifact acceptance gate rather than overstating the current evidence. I’m closing this source PR because the reviewed integration is now on main.