feat: make AGS colorshell configuration fully declarative

- Add complete colorshell v2.0.3 configuration to home/ags-config/
- Disable runner plugin and NightLight tile (incompatible with NixOS)
- Customize SCSS with full opacity (no transparency)
- Add dark pale blue color scheme in home/pywal-colors/
- Configure Papirus-Dark icon theme via home-manager
- Make ~/.config/ags/ immutable and managed by Nix store
- Auto-deploy pywal colors to ~/.cache/wal/colors.json

All AGS configuration is now reproducible and version controlled.

home/ags-config/resources/styles/_apps-window.scss

@@ -0,0 +1,50 @@
+@use "sass:color";
+@use "./colors";
+
+.apps-window .popup-window-container {
+  $radius: 48px;
+
+  padding: 28px;
+  background: colors.$bg-translucent;
+  border-radius: $radius $radius 0 0;
+
+  & entry {
+    background: transparent;
+    margin-bottom: 32px;
+    min-width: 450px;
+    padding: 14px;
+    border-radius: 18px;
+
+    &:focus-within {
+      box-shadow: inset 0 0 0 2px colors.$bg-tertiary;
+      background: rgba(colors.$bg-primary, .2);
+    }
+  }
+
+  & flowbox {
+    padding: 16px 24px;
+
+    & > flowboxchild {
+      & > button {
+        padding: 10px;
+        border-radius: 24px;
+
+        & image {
+          -gtk-icon-size: 64px;
+        }
+
+        & label {
+          margin-top: 24px;
+          text-shadow: 1px 1px 1px rgba(colors.$bg-primary, .2);
+          font-weight: 500;
+        }
+      }
+
+      &:focus > button, 
+      &:selected > button,
+      & > button:hover {
+        background-color: rgba($color: colors.$bg-secondary, $alpha: .5);
+      }
+    }
+  }
+}