Function get_media_cache_dir 

pub fn get_media_cache_dir<R: Runtime>(
    app: &AppHandle<R>,
) -> Result<PathBuf, Error>

Gets the media cache directory for temporary processing files.

Uses app_cache_dir() as base directory - files here can be deleted anytime.

Example

let cache_dir = get_media_cache_dir(&app)?;
let temp_file = cache_dir.join("temp_output.mp4");