chore: add css config path to stx.config.ts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: glennmichael123

packages/devtools/stx.config.ts

@@ -20,6 +20,7 @@ export default {
       bodyClass: 'bg-[#0a0a0f] text-zinc-50 leading-relaxed min-h-screen',
     },
   },
+  css: './crosswind.config.ts',
   router: {
     container: 'main',
   },