refactor: extract storage cache artifact helper

Author: ndycode

lib/storage.ts

@@ -20,6 +20,7 @@ import {
 	type BackupSnapshotMetadata,
 	buildMetadataSection,
 } from "./storage/backup-metadata.js";
+import { isCacheLikeBackupArtifactName } from "./storage/cache-artifacts.js";
 import { formatStorageErrorHint } from "./storage/error-hints.js";
 import { loadFlaggedAccountsFromFile } from "./storage/flagged-storage-file.js";
 import {
@@ -501,10 +502,6 @@ function withRestoreMetadata(
 	};
 }
 
-function isCacheLikeBackupArtifactName(entryName: string): boolean {
-	return entryName.toLowerCase().includes(".cache");
-}
-
 async function loadFlaggedAccountsFromPath(
 	path: string,
 ): Promise<FlaggedAccountStorageV1> {

lib/storage/cache-artifacts.ts

@@ -0,0 +1,3 @@
+export function isCacheLikeBackupArtifactName(entryName: string): boolean {
+	return entryName.toLowerCase().includes(".cache");
+}