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/is/number.ts

@@ -0,0 +1,20 @@
+// Copyright 2017-2025 @polkadot/util authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+/**
+ * @name isNumber
+ * @summary Tests for a JavaScript number.
+ * @description
+ * Checks to see if the input value is a valid number.
+ * @example
+ * <BR>
+ *
+ * ```javascript
+ * import { isNumber } from '@pezkuwi/util';
+ *
+ * console.log('isNumber', isNumber(1234)); // => true
+ * ```
+ */
+export function isNumber (value: unknown): value is number {
+  return typeof value === 'number';
+}