Format with nixfmt

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

modules/assertions.nix

@@ -186,11 +186,7 @@ in
       ++ (
         let
           allUsbDeviceKeys = lib.concatMap (
-            vm:
-            map (
-              dev:
-              "${dev.vendorId}:${dev.productId}:${toString (dev.serial or "")}"
-            ) vm.usbDevices
+            vm: map (dev: "${dev.vendorId}:${dev.productId}:${toString (dev.serial or "")}") vm.usbDevices
           ) (lib.attrValues cfg.nixosVms);
         in
         [

modules/services.nix

@@ -333,7 +333,7 @@ in
         # Persistent USB attach services (one per VM with usbDevices)
         lib.concatMap (
           vm:
-          lib.optional (vm.usbDevices != []) (
+          lib.optional (vm.usbDevices != [ ]) (
             lib.nameValuePair "vmsilo-${vm.name}-usb-attach" {
               description = "USB device attach for VM ${vm.name}";
               requires = [ "vmsilo-${vm.name}-vm.service" ];