Add vivaldi module

machines/kuro.nix

@@ -17,7 +17,8 @@
     <my/modules/graphics.nix>   # art & design
     <my/modules/vm.nix>         # virtualbox for testing
 
-    <my/modules/browser/firefox.nix>
+    # <my/modules/browser/firefox.nix>
+    <my/modules/browser/vivaldi.nix>
     <my/modules/dev/cc.nix>
     <my/modules/dev/rust.nix>
     <my/modules/editors/emacs.nix>

modules/browser/vivaldi.nix

@@ -0,0 +1,8 @@
+{ config, lib, pkgs, ... }:
+
+{
+  my.packages = with pkgs; [
+    vivaldi
+  ];
+  my.env.BROWSER = "vivaldi";
+}

modules/desktop/bspwm.nix

@@ -88,6 +88,7 @@
       vSync = true;
       opacityRules = [
         "100:class_g = 'Firefox'"
+        "100:class_g = 'Vivaldi-stable'"
         "100:class_g = 'VirtualBox Machine'"
         # Art/image programs where we need fidelity
         "100:class_g = 'Gimp'"