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/u8a/concatBuffer.ts

@@ -0,0 +1,34 @@
+// Copyright 2017-2025 @polkadot/util authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+import type { U8aLike } from '../types.js';
+
+import { u8aToU8a } from './toU8a.js';
+
+/**
+ * @name u8aConcat
+ * @summary Creates a concatenated Uint8Array from the inputs.
+ * @description
+ * Concatenates the input arrays into a single `UInt8Array`.
+ * @example
+ * <BR>
+ *
+ * ```javascript
+ * import { { u8aConcat } from '@pezkuwi/util';
+ *
+ * u8aConcat(
+ *   new Uint8Array([1, 2, 3]),
+ *   new Uint8Array([4, 5, 6])
+ * ); // [1, 2, 3, 4, 5, 6]
+ * ```
+ */
+export function u8aConcat (...list: readonly U8aLike[]): Uint8Array {
+  const count = list.length;
+  const u8as = new Array<Uint8Array>(count);
+
+  for (let i = 0; i < count; i++) {
+    u8as[i] = u8aToU8a(list[i]);
+  }
+
+  return Uint8Array.from(Buffer.concat(u8as));
+}