refactor(audio): simplify media controls

configs/nixos/modules/desktop/utilities/audio.nix

@@ -6,37 +6,33 @@
   ...
 }:
 # PipeWire as the desktop audio server.
+let
+  mediaKey = keys: command: {
+    inherit keys;
+    locked = true;
+    action = {
+      kind = "exec";
+      command = "${lib.getExe pkgs.playerctl} ${command}";
+    };
+  };
+in
 {
   options.modules.desktop.utilities.audio.enable = lib.mkEnableOption "the PipeWire audio server";
 
   config = lib.mkIf config.modules.desktop.utilities.audio.enable {
+    # Realtime scheduling for the audio threads, so playback survives load.
+    security.rtkit.enable = true;
+
+    services.pipewire = {
+      enable = true;
+      alsa.enable = true;
+      pulse.enable = true;
+    };
+
     registry.keybind.${config.networking.hostName} = {
-      media-play = {
-        keys = "XF86AudioPlay";
-        locked = true;
-        action = {
-          kind = "exec";
-          command = "${lib.getExe pkgs.playerctl} play-pause";
-        };
-      };
-
-      media-next = {
-        keys = "XF86AudioNext";
-        locked = true;
-        action = {
-          kind = "exec";
-          command = "${lib.getExe pkgs.playerctl} next";
-        };
-      };
-
-      media-previous = {
-        keys = "XF86AudioPrev";
-        locked = true;
-        action = {
-          kind = "exec";
-          command = "${lib.getExe pkgs.playerctl} previous";
-        };
-      };
+      media-play = mediaKey "XF86AudioPlay" "play-pause";
+      media-next = mediaKey "XF86AudioNext" "next";
+      media-previous = mediaKey "XF86AudioPrev" "previous";
     };
 
     registry.waybar.${config.networking.hostName} = {
@@ -66,14 +62,5 @@
         };
       };
     };
-
-    # Realtime scheduling for the audio threads, so playback survives load.
-    security.rtkit.enable = true;
-
-    services.pipewire = {
-      enable = true;
-      alsa.enable = true;
-      pulse.enable = true;
-    };
   };
 }