magicman: add v4l2loopback virtual camera support

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

hosts/magicman/configuration.nix

@@ -14,6 +14,10 @@
     "rd.udev.log_level=3"
   ];
 
+  boot.extraModprobeConfig = ''
+    options v4l2loopback exclusive_caps=1 card_label="Virtual Camera"
+  '';
+
   boot.loader.systemd-boot.configurationLimit = 3;
 
   boot.initrd.systemd.enable = true;
@@ -85,6 +89,7 @@
     wget
     curl
     git
+    v4l-utils
   ];
 
   # Do NOT change this value unless you have manually inspected all the changes it would make to your configuration,

hosts/magicman/hardware-configuration.nix

@@ -21,8 +21,11 @@
     "sdhci_pci"
   ];
   boot.initrd.kernelModules = [ "i915" ];
-  boot.kernelModules = [ "kvm-intel" ];
-  boot.extraModulePackages = [ ];
+  boot.kernelModules = [
+    "kvm-intel"
+    "v4l2loopback"
+  ];
+  boot.extraModulePackages = with config.boot.kernelPackages; [ v4l2loopback ];
 
   fileSystems."/" = {
     device = "/dev/disk/by-uuid/31b20f4c-24bb-4fd1-9a3e-8ccc19fe3d64";