hold overlays correctly

packages/applicative-wallpaper.nix

@@ -0,0 +1,38 @@
+{
+  runCommand,
+  fetchurl,
+  imagemagick,
+  colors,
+}:
+let
+  backgroundColor = colors.withHashtag.base06;
+  foregroundColor = colors.withHashtag.base01;
+  width = 1920;
+  height = 1080;
+
+  svgUrl = "https://applicative.systems/_astro/logo-full.D8zRvqBZ.svg";
+  logoSvg = fetchurl {
+    url = svgUrl;
+    hash = "sha256-qXDIEZsAPn4eUJ3kb5U6L3PMUCtWGYqhqyIaBt7FntE=";
+  };
+in
+runCommand "applicative-wallpaper.png"
+  {
+    nativeBuildInputs = [ imagemagick ];
+  }
+  ''
+    # 1. We use -background to set the canvas color
+    # 2. We use -fuzz and -opaque to replace the logo's internal colors
+    # 3. We use -gravity and -extent to center it on a wallpaper-sized canvas
+
+    convert \
+      -background none \
+      -density 300 \
+      "${logoSvg}" \
+      -fuzz 100% -fill "${foregroundColor}" -opaque black \
+      -resize 800x800 \
+      -gravity center \
+      -background "${backgroundColor}" \
+      -extent ${toString width}x${toString height} \
+      $out
+  ''