Add Pezkuwi SDK UI - Polkadot.js Apps clone

- Clone Polkadot.js Apps repository
- Update package.json with Pezkuwi branding
- Add Pezkuwi endpoint to production chains (wss://pezkuwichain.app:9944)
- Create comprehensive README for SDK UI
- Set up project structure with all packages

Next steps:
- Apply Kurdistan colors (Kesk, Sor, Zer, Spi + Black) to UI theme
- Replace logos with Pezkuwi branding
- Test build and deployment

pezkuwi-sdk-ui/packages/page-staking2/src/useCache.ts

@@ -0,0 +1,57 @@
+// Copyright 2017-2025 @polkadot/app-staking authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+import { useEffect } from 'react';
+
+export interface CacheValue<T> {
+  value?: T;
+}
+
+type CacheMapKey = `use${'Exposure' | 'Heartbeat'}`;
+
+type CacheValKey = `use${'ElectedValidators' | 'Points' | 'ValidatorsActive' | 'ValidatorsAll' | 'ValidatorsWaiting'}`;
+
+const cacheMap: Record<CacheMapKey, Record<string, CacheValue<any>>> = {
+  useExposure: {},
+  useHeartbeat: {}
+};
+
+const cacheVal: Record<CacheValKey, CacheValue<any>> = {
+  useElectedValidators: {},
+  usePoints: {},
+  useValidatorsActive: {},
+  useValidatorsAll: {},
+  useValidatorsWaiting: {}
+};
+
+export function clearCache (): void {
+  for (const k of Object.keys(cacheMap)) {
+    cacheMap[k as CacheMapKey] = {};
+  }
+
+  for (const k of Object.keys(cacheVal)) {
+    cacheVal[k as CacheValKey] = {};
+  }
+}
+
+export function useCacheMap <T> (section: CacheMapKey, id: string, value?: T): T | undefined {
+  // update the cached result on value changes
+  useEffect((): void => {
+    if (value) {
+      cacheMap[section][id] = { value };
+    }
+  }, [id, section, value]);
+
+  return value || (cacheMap[section][id] as CacheValue<T>)?.value;
+}
+
+export function useCacheValue <T> (section: CacheValKey, value?: T): T | undefined {
+  // update the cached result on value changes
+  useEffect((): void => {
+    if (value) {
+      cacheVal[section] = { value };
+    }
+  }, [section, value]);
+
+  return value || (cacheVal[section] as CacheValue<T>)?.value;
+}