PiaNut Windows engine override

Wrapper: media_kit_libs_windows_video 1.0.11, MIT, unchanged native plugin.
PiaNut changes: pin muxer-capable LGPL mpv archive and extract at configure
time; no machine-wide shell deletion or long MSBuild extraction target names.

Native archive, unmodified:
https://github.com/zhongfly/mpv-winbuild/releases/download/2026-10-25-baa3e11d42/mpv-dev-lgpl-x86_64-20261025-git-baa3e11d42.7z
SHA256: 6429ebba4b6bfc5dd18ac5ac084f00776db0db4e767ef1bfb815fc78ec5bda2a
libmpv-2.dll SHA256: 0f2382ff89ef9966353dc0770b833c6a4551643452ec69fdeb373e28809bd7b4
Baseline x86_64 (not x86_64-v3), LGPL variant. Third-party builds listed by mpv.io.

Build scripts and source references:
https://github.com/zhongfly/mpv-winbuild/tree/b120d7d8a64d17bd40b893f585429ef3845ac766
mpv commit: baa3e11d42cb7978da634a8a6a3a55fe074d01be
https://github.com/mpv-player/mpv/tree/baa3e11d42cb7978da634a8a6a3a55fe074d01be
mpv LGPLv2.1-or-later; bundled FFmpeg LGPLv3, per upstream build documentation.
The binary is dynamically loaded; users may replace libmpv-2.dll with a
compatible build. Do not strip its license notices when redistributing.

The archive is preserved locally because upstream release downloads rotate.
Windows native playback/seek/subtitle/record/replay evidence is generated by
tool/windows_native_probe.py. The original 2023 DLL has no muxing support.
