Vanguard: enable v4l2loopback for virtual webcam in OBS

Add obs-backgroundremoval plugin

Enable polkit

home/games/obs/default.nix

@@ -5,6 +5,7 @@
     plugins = with pkgs.obs-studio-plugins; [
       wlrobs
       obs-vkcapture
+      obs-backgroundremoval
       obs-pipewire-audio-capture
       obs-gstreamer
       input-overlay

hosts/Vanguard/configuration.nix

@@ -1 +1,7 @@
-{ ... }: { system.autoUpgrade.allowReboot = false; }
+{ config, ... }: {
+  system.autoUpgrade.allowReboot = false;
+  boot.extraModulePackages = with config.boot.kernelPackages; [ v4l2loopback ];
+  boot.extraModprobeConfig = ''
+    options v4l2loopback devices=1 video_nr=1 card_label="OBS Cam" exclusive_caps=1
+  '';
+}

system/desktop.nix

@@ -7,7 +7,10 @@
     glib
     gsettings-desktop-schemas
   ];
-  security.rtkit.enable = true;
+  security = {
+    polkit.enable = true;
+    rtkit.enable = true;
+  };
   sound.enable = true;
   hardware = {
     pulseaudio.enable = false;