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/_logout-menu.scss

@@ -0,0 +1,52 @@
+@use "./colors";
+
+.logout-menu-container {
+  background: rgba($color: colors.$bg-translucent-primary, $alpha: .4);
+
+  .top {
+    .time {
+      font-size: 128px;
+      font-weight: 900;
+      color: colors.$fg-primary;
+      text-shadow: 1px 1px 2px colors.$bg-translucent;
+    }
+    .date {
+      font-size: 24px;
+      font-weight: 500;
+      text-shadow: 1px 1px 2px colors.$bg-translucent;
+    }
+  }
+  .button-row {
+    $radius: 32px;
+
+    all: unset;
+    margin: 0 150px;
+
+    & > button {
+      & image {
+        -gtk-icon-size: 128px;
+      }
+
+      &:focus-visible {
+        box-shadow: inset 0 0 0 5px colors.$fg-primary;
+      }
+
+      &:active {
+        border-radius: calc($radius - 6px);
+      }
+
+      margin: 0 4px;
+      border-radius: 6px;
+
+      &:first-child:not(:active) {
+        border-top-left-radius: $radius;
+        border-bottom-left-radius: $radius;
+      }
+
+      &:last-child:not(:active) {
+        border-top-right-radius: $radius;
+        border-bottom-right-radius: $radius;
+      }
+    }
+  }
+}