fix(docs): expand tailwind safelist for playground color palette

apps/docs/app/globals.css

@@ -4,6 +4,36 @@
 @import "../node_modules/tw-shimmer/src/index.css";
 @source "../node_modules/@assistant-ui/chords/dist";
 
+/* Safelist color utilities for playground dynamic class inputs.
+   Tailwind 4 @source inline() scans for literal class names — no brace expansion. */
+@source inline("
+  bg-zinc-100 bg-zinc-300 bg-zinc-500 bg-zinc-700 bg-zinc-900
+  bg-blue-100 bg-blue-300 bg-blue-500 bg-blue-700 bg-blue-900
+  bg-indigo-100 bg-indigo-300 bg-indigo-500 bg-indigo-700 bg-indigo-900
+  bg-violet-100 bg-violet-300 bg-violet-500 bg-violet-700 bg-violet-900
+  bg-rose-100 bg-rose-300 bg-rose-500 bg-rose-700 bg-rose-900
+  bg-red-100 bg-red-300 bg-red-500 bg-red-700 bg-red-900
+  bg-green-100 bg-green-300 bg-green-500 bg-green-700 bg-green-900
+  bg-amber-100 bg-amber-300 bg-amber-500 bg-amber-700 bg-amber-900
+  bg-black bg-white bg-transparent
+  text-zinc-100 text-zinc-300 text-zinc-500 text-zinc-700 text-zinc-900
+  text-blue-100 text-blue-300 text-blue-500 text-blue-700 text-blue-900
+  text-indigo-100 text-indigo-300 text-indigo-500 text-indigo-700 text-indigo-900
+  text-violet-100 text-violet-300 text-violet-500 text-violet-700 text-violet-900
+  text-rose-100 text-rose-300 text-rose-500 text-rose-700 text-rose-900
+  text-red-100 text-red-300 text-red-500 text-red-700 text-red-900
+  text-green-100 text-green-300 text-green-500 text-green-700 text-green-900
+  text-amber-100 text-amber-300 text-amber-500 text-amber-700 text-amber-900
+  text-black text-white
+  size-4 size-5 size-6 size-7 size-8 size-9 size-10 size-11 size-12
+  rounded-none rounded-sm rounded-md rounded-lg rounded-xl rounded-2xl rounded-3xl rounded-full
+  p-0 p-1 p-2 p-3 p-4 p-5 p-6
+  px-0 px-1 px-2 px-3 px-4 px-5 px-6
+  py-0 py-1 py-2 py-3 py-4 py-5 py-6
+  items-center justify-center flex inline-flex
+  gap-1 gap-2 gap-3 gap-4
+");
+
 /* Align Fumadocs background with landing page palette */
 :root {
   --color-fd-background: #FAF9F6;