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/ProtectedRoute.tsx

@@ -0,0 +1,34 @@
+import React from 'react';
+import { Navigate } from 'react-router-dom';
+import { useAuth } from '@/contexts/AuthContext';
+import { Loader2 } from 'lucide-react';
+
+interface ProtectedRouteProps {
+  children: React.ReactNode;
+  requireAdmin?: boolean;
+}
+
+export const ProtectedRoute: React.FC<ProtectedRouteProps> = ({ 
+  children, 
+  requireAdmin = false 
+}) => {
+  const { user, loading, isAdmin } = useAuth();
+
+  if (loading) {
+    return (
+      <div className="min-h-screen flex items-center justify-center bg-gray-900">
+        <Loader2 className="w-8 h-8 animate-spin text-green-500" />
+      </div>
+    );
+  }
+
+  if (!user) {
+    return <Navigate to="/login" replace />;
+  }
+
+  if (requireAdmin && !isAdmin) {
+    return <Navigate to="/" replace />;
+  }
+
+  return <>{children}</>;
+};