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/upperFirst.spec.ts

@@ -0,0 +1,41 @@
+// Copyright 2017-2025 @polkadot/util authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+/// <reference types="@polkadot/dev-test/globals.d.ts" />
+
+import { perf } from '../test/index.js';
+import { stringUpperFirst } from './index.js';
+
+describe('stringUpperFirst', (): void => {
+  it("uppers the first letter if it's a capital letter", (): void => {
+    expect(
+      stringUpperFirst('ABC')
+    ).toBe('ABC');
+  });
+
+  it("uppers the first letter if it's a lowercase letter", (): void => {
+    expect(
+      stringUpperFirst('abc')
+    ).toBe('Abc');
+  });
+
+  it("uppers the first letter if it's a lowercase letter (String)", (): void => {
+    expect(
+      stringUpperFirst(String('abc'))
+    ).toBe('Abc');
+  });
+
+  it('returns undefined as empty', (): void => {
+    expect(
+      stringUpperFirst()
+    ).toBe('');
+  });
+
+  it('returns null as empty', (): void => {
+    expect(
+      stringUpperFirst(null)
+    ).toBe('');
+  });
+
+  perf('stringUpperFirst', 1_000_000, [['helloWorldSomething']], stringUpperFirst);
+});