waybar updates

modules/nixos/hardware/audio/default.nix

@@ -23,5 +23,42 @@ in {
       wireplumber.enable = true;
       jack.enable = true;
     };
+
+    systemd.user.services.cava-combine-inputs = {
+      description = "Combine MOTU M4 Line Inputs L/R for Cava";
+
+      # Ensure this runs after pipewire-pulse is started
+      after = ["pipewire-pulse.service"];
+      wants = ["pipewire-pulse.service"]; # Start pipewire-pulse if not already running
+
+      # Make it part of the default user session target
+      wantedBy = ["default.target"];
+
+      # Service configuration details
+      serviceConfig = {
+        Type = "oneshot"; # Run the command once and exit
+        # Use RemainAfterExit if you want the service to show as 'active' after running
+        # RemainAfterExit = true;
+
+        # Command to execute. Use full paths for robustness.
+        # We use sh -c to run multiple commands sequentially.
+        # pactl is provided by the pulseaudio package.
+        ExecStart = ''
+          ${pkgs.runtimeShell} -c '
+            echo "Attempting to load Cava combine modules..."
+            # Load null sink (returns non-zero if it fails AND module doesn't exist)
+            ${pkgs.pulseaudio}/bin/pactl load-module module-null-sink sink_name=cava-line-in sink_properties=device.description="Cava_Combined_LineIn"
+            # Load loopbacks (returns non-zero on failure)
+            ${pkgs.pulseaudio}/bin/pactl load-module module-loopback source="alsa_input.usb-MOTU_M4_M4MA03F7DV-00.HiFi__Line3__source" sink=cava-line-in latency_msec=10
+            ${pkgs.pulseaudio}/bin/pactl load-module module-loopback source="alsa_input.usb-MOTU_M4_M4MA03F7DV-00.HiFi__Line4__source" sink=cava-line-in latency_msec=10
+            echo "Finished loading Cava combine modules (ignore errors if already loaded)."
+            # Exit successfully even if modules were already loaded (pactl might return 0)
+            exit 0
+        '';
+
+        # Prevent service from restarting automatically
+        Restart = "no";
+      };
+    };
   };
 }