add option to use sveltekit's fetch for seeding db

src/lib/db/client-db/seed.ts

@@ -36,14 +36,16 @@ function ensureBrowser() {
  *
  * @param opts.version Bump to force users to refresh from the shipped snapshot
  * @param opts.force If true, reseed even if already seeded for this version
+ * @param opts.fetch Optional fetch implementation (prefer the one from load)
  */
 export async function ensureSeeded(
-	opts: { version?: number; force?: boolean } = {},
+	opts: { version?: number; force?: boolean; fetch?: typeof fetch } = {},
 ): Promise<void> {
 	ensureBrowser();
 
 	const version = opts.version ?? AMQ_DB_SEED_VERSION;
 	const key = seededStorageKey(version);
+	const fetcher = opts.fetch ?? fetch;
 
 	if (!opts.force && localStorage.getItem(key) === "1") return;
 
@@ -56,7 +58,7 @@ export async function ensureSeeded(
 
 		const url = asset(SEED_ASSET_PATH);
 
-		const res = await fetch(url, { cache: "no-cache" });
+		const res = await fetcher(url, { cache: "no-cache" });
 		if (!res.ok) {
 			throw new Error(
 				`Failed to fetch seed DB from ${url}: ${res.status} ${res.statusText}`,