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/keyring/src/pairs.ts

@@ -0,0 +1,41 @@
+// Copyright 2017-2025 @polkadot/keyring authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+import type { KeyringPair, KeyringPairs } from './types.js';
+
+import { isHex, isU8a, u8aToHex, u8aToU8a } from '@pezkuwi/util';
+import { decodeAddress } from '@pezkuwi/util-crypto';
+
+type KeyringPairMap = Record<string, KeyringPair>;
+
+export class Pairs implements KeyringPairs {
+  readonly #map: KeyringPairMap = {};
+
+  public add (pair: KeyringPair): KeyringPair {
+    this.#map[decodeAddress(pair.address).toString()] = pair;
+
+    return pair;
+  }
+
+  public all (): KeyringPair[] {
+    return Object.values(this.#map);
+  }
+
+  public get (address: string | Uint8Array): KeyringPair {
+    const pair = this.#map[decodeAddress(address).toString()];
+
+    if (!pair) {
+      throw new Error(`Unable to retrieve keypair '${
+        isU8a(address) || isHex(address)
+          ? u8aToHex(u8aToU8a(address))
+          : address
+      }'`);
+    }
+
+    return pair;
+  }
+
+  public remove (address: string | Uint8Array): void {
+    delete this.#map[decodeAddress(address).toString()];
+  }
+}