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/react-hooks/src/useNonEmptyString.ts

@@ -0,0 +1,17 @@
+// Copyright 2017-2025 @polkadot/react-hooks authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+import type { FormField } from './useFormField.js';
+
+import { createNamedHook } from './createNamedHook.js';
+import { useFormField } from './useFormField.js';
+
+function isValid (value?: string | null): boolean {
+  return (value && value.length > 0) || false;
+}
+
+function useNonEmptyStringImpl (initialValue = ''): FormField<string> {
+  return useFormField(initialValue, isValid);
+}
+
+export const useNonEmptyString = createNamedHook('useNonEmptyString', useNonEmptyStringImpl);