Feature: prevent app change media volume

[Undefined-User]

Applications launched by PlayCover cannot read the current media volume level in macOS, but they can modify the media volume level normally. Some applications may assume the current media volume is 100% when reading fails. If you accidentally adjust the volume in these applications, the macOS media volume will suddenly become extremely loud, which can damage your hearing.

This PR contains two modifications: it will trick the application into believing the current media volume is 30%, and it will discard any changes the application makes to the media volume value. You can still adjust the media volume in macOS using headphone buttons, keyboard function keys, or the system volume slider.

[Undefined-User]

PR is ready for review, plz add reviewer~ @TheMoonThatRises

[Catta1997]

Imo the best things is add a slider in app settings where you can choose app volume so you can also mute an app if you want

[Undefined-User]

Imo the best things is add a slider in app settings where you can choose app volume so you can also mute an app if you want

@Catta1997 However, for macOS users, even if an app within PlayCover detects the current media volume as zero, the actual media volume output will only be controlled by macOS (app volume cannot be independent of macOS volume, similar to app behavior in iOS). Therefore, controlling media volume through macOS's built-in functions is more convenient, and adding a volume slider in the settings is unnecessary.

[Catta1997]

Imo the best things is add a slider in app settings where you can choose app volume so you can also mute an app if you want

@Catta1997 However, for macOS users, even if an app within PlayCover detects the current media volume as zero, the actual media volume output will only be controlled by macOS (app volume cannot be independent of macOS volume, similar to app behavior in iOS). Therefore, controlling media volume through macOS's built-in functions is more convenient, and adding a volume slider in the settings is unnecessary.

Yeah but my idea was not to a “global” usage but when I want to have more apps and for a specific run of the game remove the volume without use a 3rd party app that do this. But seems that cannot be done. Rip