feat(bucket): expose the underlying S3 client through getStorageClient()

test/test.node+deno.ts

@@ -24,6 +24,17 @@ tap.test('should create a valid smartbucket', async () => {
   expect(myBucket.name).toEqual(bucketName);
 });
 
+tap.test('should expose the underlying S3 client via getStorageClient()', async () => {
+  const client = myBucket.getStorageClient();
+  expect(client).toBeDefined();
+  expect(typeof (client as any).send).toEqual('function');
+  // The returned client must be the exact same instance as the parent
+  // SmartBucket's storageClient — not a copy. Use identity comparison
+  // because the S3Client contains circular references and cannot be
+  // deep-compared by tapbundle's toEqual.
+  expect(client === testSmartbucket.storageClient).toBeTrue();
+});
+
 tap.test('should clean all contents', async () => {
   await myBucket.cleanAllContents();
   expect(await myBucket.fastExists({ path: 'hithere/socool.txt' })).toBeFalse();