make sound modifier keys work by using pipewire

configuration.nix

@@ -88,7 +88,14 @@
 
   # Enable sound.
   sound.enable = true;
-  hardware.pulseaudio.enable = true;
+  services.pipewire = {
+    enable = true;
+    alsa.enable = true;
+    alsa.support32Bit = true;
+    jack.enable = true;
+    pulse.enable = true;
+  };
+  hardware.pulseaudio.enable = false;
 
   # Enable touchpad support (enabled default in most desktopManager).
   services.libinput = {

hyperland/default.nix

@@ -121,5 +121,22 @@
           )
           10)
       );
+      # Bind flags
+      # l -> locked, will also work when an input inhibitor (e.g. a lockscreen) is active.
+      # r -> release, will trigger on release of a key.
+      # e -> repeat, will repeat when held.
+      # n -> non-consuming, key/mouse events will be passed to the active window in addition to triggering the dispatcher.
+      # m -> mouse, see below
+      # t -> transparent, cannot be shadowed by other binds.
+      # i -> ignore mods, will ignore modifiers.
+      binde = [
+        ", XF86AudioRaiseVolume, exec, wpctl set-volume @DEFAULT_AUDIO_SINK@ 5%+ --limit 1.3"
+      ];
+      bindle = [
+        ", XF86AudioLowerVolume, exec, wpctl set-volume @DEFAULT_AUDIO_SINK@ 5%-"
+      ];
+      bindl = [
+        ", XF86AudioMute,        exec, wpctl set-mute   @DEFAULT_AUDIO_SINK@ toggle"
+      ];
   };
 }