feat: Integrate Polkadot.js API and wallet connection

Major Changes:
- Added @polkadot/api and related dependencies
- Created PolkadotContext for blockchain connection
- Implemented NetworkStats component with live data
- Added PolkadotWalletButton for wallet integration
- Connected to local validator node (ws://127.0.0.1:9944)

Features:
- Live block number and hash display
- Real-time validator count
- Network connection status monitoring
- Polkadot.js extension integration
- Multi-account support
- Account switching capability

Technical:
- RPC endpoint: ws://127.0.0.1:9944
- Auto-reconnect on disconnect
- TypeScript integration
- React hooks for state management

src/main.tsx

@@ -2,6 +2,7 @@ import { createRoot } from 'react-dom/client'
 import App from './App.tsx'
 import { WalletProvider } from './contexts/WalletContext'
 import { WebSocketProvider } from './contexts/WebSocketContext'
+import { PolkadotProvider } from './contexts/PolkadotContext'
 import './index.css'
 import './i18n/config'
 
@@ -14,9 +15,11 @@ declare global {
 
 // Remove dark mode class addition
 createRoot(document.getElementById("root")!).render(
-  <WalletProvider>
-    <WebSocketProvider>
-      <App />
-    </WebSocketProvider>
-  </WalletProvider>
-);
+  <PolkadotProvider endpoint="ws://127.0.0.1:9944">
+    <WalletProvider>
+      <WebSocketProvider>
+        <App />
+      </WebSocketProvider>
+    </WalletProvider>
+  </PolkadotProvider>
+);