fix(13-05): wire /static/tailwind.css into catalog page head

backend/internal/web/ui/catalog/catalog.templ

@@ -11,6 +11,7 @@ templ CatalogPage() {
 			<meta charset="UTF-8"/>
 			<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
 			<title>Component Catalog</title>
+			<link rel="stylesheet" href="/static/tailwind.css"/>
 			<style>
 				/* Catalog shell — minimal reset only, no app.css import (D-A04) */
 				*, *::before, *::after { box-sizing: border-box; }