feat: improve combination search and offline build

src/lib/data/chart-loader.ts

@@ -0,0 +1,7 @@
+import type { ExactSongChart } from '$lib/engine/index.ts';
+
+export async function loadExactSongChart(path: string): Promise<ExactSongChart> {
+  const response = await fetch(path);
+  if (!response.ok) throw new Error('정확 채보 데이터를 불러오지 못했습니다.');
+  return response.json() as Promise<ExactSongChart>;
+}