feat(player): add embedded-mpv player for macOS as experimental feature

- Introduced tooling for building and staging the macOS `libmpv` runtime for IPTVnator's embedded MPV player.
- Added `build-macos-runtime.mjs` for building an LGPL-compatible runtime from source.
- Created `stage-macos-runtime.mjs` for staging the built runtime artifacts.
- Implemented validation for the packaged embedded MPV runtime in `electron-after-pack.cjs` and `embedded-mpv-macos.cjs`.
- Updated packaging scripts to ensure the embedded MPV runtime is correctly integrated and validated during the build process.
- Added README files to document the expected layout and usage for the embedded MPV runtime artifacts.

Entire-Checkpoint: c6e522b4276c

libs/shared/interfaces/src/lib/settings.interface.ts

@@ -8,6 +8,7 @@ import { Theme } from './theme.enum';
 export enum VideoPlayer {
     VideoJs = 'videojs',
     Html5Player = 'html5',
+    EmbeddedMpv = 'embedded-mpv',
     MPV = 'mpv',
     VLC = 'vlc',
     ArtPlayer = 'artplayer',