패키지 버전 업데이트 및 SvelteKit 3, Tailwind CSS 4로 마이그레이션

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/params.ts

@@ -0,0 +1,9 @@
+import { defineParams } from "@sveltejs/kit/params";
+
+const matchThumbnail = (param: string) => {
+  return param === "thumbnail";
+};
+
+export const params = defineParams({
+  thumbnail: (param) => (matchThumbnail(param) ? param : undefined),
+});