Reorganize repository into monorepo structure

Restructured the project to support multiple frontend applications:
- Move web app to web/ directory
- Create pezkuwi-sdk-ui/ for Polkadot SDK clone (planned)
- Create mobile/ directory for mobile app development
- Add shared/ directory with common utilities, types, and blockchain code
- Update README.md with comprehensive documentation
- Remove obsolete DKSweb/ directory

This monorepo structure enables better code sharing and organized
development across web, mobile, and SDK UI projects.

web/src/components/wallet/WalletButton.tsx

@@ -0,0 +1,101 @@
+import React from 'react';
+import { Wallet, LogOut, AlertCircle } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuLabel,
+  DropdownMenuSeparator,
+  DropdownMenuTrigger,
+} from '@/components/ui/dropdown-menu';
+import { useWallet } from '@/contexts/WalletContext';
+import { formatAddress, formatBalance } from '@/lib/wallet';
+import { Badge } from '@/components/ui/badge';
+
+export const WalletButton: React.FC = () => {
+  const { 
+    isConnected, 
+    address, 
+    balance, 
+    chainId,
+    error,
+    connectMetaMask,
+    disconnect,
+    switchNetwork
+  } = useWallet();
+
+  if (!isConnected) {
+    return (
+      <div className="flex items-center gap-2">
+        {error && (
+          <div className="flex items-center gap-2 text-sor text-sm">
+            <AlertCircle className="h-4 w-4" />
+            <span>{error}</span>
+          </div>
+        )}
+        <Button 
+          onClick={connectMetaMask}
+          className="bg-kesk hover:bg-kesk/90 text-white"
+        >
+          <Wallet className="mr-2 h-4 w-4" />
+          Connect Wallet
+        </Button>
+      </div>
+    );
+  }
+
+  const isCorrectNetwork = chainId === '0x2329';
+
+  return (
+    <DropdownMenu>
+      <DropdownMenuTrigger asChild>
+        <Button variant="outline" className="border-kesk/20 hover:border-kesk">
+          <div className="flex items-center gap-2">
+            <Wallet className="h-4 w-4 text-kesk" />
+            <div className="text-left">
+              <div className="text-sm font-medium">{formatAddress(address!)}</div>
+              <div className="text-xs text-muted-foreground">{formatBalance(balance)} PZK</div>
+            </div>
+            {!isCorrectNetwork && (
+              <Badge variant="destructive" className="ml-2 bg-sor">
+                Wrong Network
+              </Badge>
+            )}
+          </div>
+        </Button>
+      </DropdownMenuTrigger>
+      <DropdownMenuContent align="end" className="w-56">
+        <DropdownMenuLabel>Wallet Details</DropdownMenuLabel>
+        <DropdownMenuSeparator />
+        <div className="px-2 py-1.5">
+          <div className="text-sm text-muted-foreground">Address</div>
+          <div className="text-sm font-mono">{formatAddress(address!)}</div>
+        </div>
+        <div className="px-2 py-1.5">
+          <div className="text-sm text-muted-foreground">Balance</div>
+          <div className="text-sm font-medium">{formatBalance(balance)} PZK</div>
+        </div>
+        <div className="px-2 py-1.5">
+          <div className="text-sm text-muted-foreground">Network</div>
+          <div className="text-sm font-medium">
+            {isCorrectNetwork ? 'PezkuwiChain' : 'Unknown Network'}
+          </div>
+        </div>
+        <DropdownMenuSeparator />
+        {!isCorrectNetwork && (
+          <>
+            <DropdownMenuItem onClick={switchNetwork} className="text-zer">
+              Switch to PezkuwiChain
+            </DropdownMenuItem>
+            <DropdownMenuSeparator />
+          </>
+        )}
+        <DropdownMenuItem onClick={disconnect} className="text-sor">
+          <LogOut className="mr-2 h-4 w-4" />
+          Disconnect
+        </DropdownMenuItem>
+      </DropdownMenuContent>
+    </DropdownMenu>
+  );
+};