Initial rebrand: @polkadot -> @pezkuwi (14 packages)

- Package namespace: @polkadot/* -> @pezkuwi/*
- Repository: polkadot-js/common -> pezkuwichain/pezkuwi-common
- Author: Pezkuwi Team <team@pezkuwichain.io>

Core packages:
- @pezkuwi/util (utilities)
- @pezkuwi/util-crypto (crypto primitives)
- @pezkuwi/keyring (account management)
- @pezkuwi/networks (chain metadata)
- @pezkuwi/hw-ledger (Ledger hardware wallet)
- @pezkuwi/x-* (10 polyfill packages)

Total: 14 packages
Upstream: polkadot-js/common v14.0.1

packages/util/src/string/toU8a.spec.ts

@@ -0,0 +1,31 @@
+// Copyright 2017-2025 @polkadot/util authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+/// <reference types="@polkadot/dev-test/globals.d.ts" />
+
+import { stringToU8a } from '../index.js';
+
+const RUSS_HELLO = new Uint8Array([208, 159, 209, 128, 208, 184, 208, 178, 208, 181, 209, 130, 44, 32, 208, 188, 208, 184, 209, 128, 33]);
+
+describe('stringToU8a', (): void => {
+  it('decodes to an empty string for undefined/null', (): void => {
+    expect(
+      stringToU8a()
+    ).toEqual(new Uint8Array());
+    expect(
+      stringToU8a(null)
+    ).toEqual(new Uint8Array());
+  });
+
+  it('encodes the string correctly', (): void => {
+    expect(
+      stringToU8a('Привет, мир!')
+    ).toEqual(RUSS_HELLO);
+  });
+
+  it('encodes the string correctly (String)', (): void => {
+    expect(
+      stringToU8a(String('Привет, мир!'))
+    ).toEqual(RUSS_HELLO);
+  });
+});