Add audio subsystem with mute and volume controls

Update flake.lock dependencies to latest revisions

src/app/threads/mod.rs

@@ -1,5 +1,7 @@
+pub mod audio;
 pub mod events;
 pub mod handle_events;
 
+pub use audio::{AudioCmd, SoundrackParts, handle_audio};
 pub use events::AppEvent;
 pub use handle_events::handle_events;