Copy SoundBase/SoundData/SoundInstance*/SoundManager*/Type from 40250 and
implement the AIL_* calls they make in MilesAil.cpp (2D pan, 3D distance and
listener pan, threaded stream decode, loop counts). The SDL host drains the
mixer. CSoundManager is created/updated/destroyed where 40250 does it and the
old AudioCommands bridge is removed. Port-map MilesLib 142/142 PORTED.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>