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/contexts/AuthContext.tsx

@@ -0,0 +1,217 @@
+import React, { createContext, useContext, useEffect, useState } from 'react';
+import { supabase } from '@/lib/supabase';
+import { User } from '@supabase/supabase-js';
+
+interface AuthContextType {
+  user: User | null;
+  loading: boolean;
+  isAdmin: boolean;
+  signIn: (email: string, password: string) => Promise<{ error: any }>;
+  signUp: (email: string, password: string, username: string, referralCode?: string) => Promise<{ error: any }>;
+  signOut: () => Promise<void>;
+  checkAdminStatus: () => Promise<boolean>;
+}
+
+// Demo/Founder account credentials from environment variables
+// ⚠️ SECURITY: Never hardcode credentials in source code!
+const FOUNDER_ACCOUNT = {
+  email: import.meta.env.VITE_DEMO_FOUNDER_EMAIL || '',
+  password: import.meta.env.VITE_DEMO_FOUNDER_PASSWORD || '',
+  id: import.meta.env.VITE_DEMO_FOUNDER_ID || 'founder-001',
+  user_metadata: {
+    full_name: 'Satoshi Qazi Muhammed',
+    phone: '+9647700557978',
+    recovery_email: 'satoshi@pezkuwichain.io',
+    founder: true
+  }
+};
+
+// Check if demo mode is enabled
+const DEMO_MODE_ENABLED = import.meta.env.VITE_ENABLE_DEMO_MODE === 'true';
+
+const AuthContext = createContext<AuthContextType | undefined>(undefined);
+
+export const useAuth = () => {
+  const context = useContext(AuthContext);
+  if (!context) {
+    throw new Error('useAuth must be used within an AuthProvider');
+  }
+  return context;
+};
+
+export const AuthProvider: React.FC<{ children: React.ReactNode }> = ({ children }) => {
+  const [user, setUser] = useState<User | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [isAdmin, setIsAdmin] = useState(false);
+
+  useEffect(() => {
+    // Check active sessions and sets the user
+    supabase.auth.getSession().then(({ data: { session } }) => {
+      setUser(session?.user ?? null);
+      if (session?.user) {
+        checkAdminStatus();
+      }
+      setLoading(false);
+    }).catch(() => {
+      // If Supabase is not available, continue without auth
+      setLoading(false);
+    });
+
+    // Listen for changes on auth state
+    const { data: { subscription } } = supabase.auth.onAuthStateChange((_event, session) => {
+      setUser(session?.user ?? null);
+      if (session?.user) {
+        checkAdminStatus();
+      }
+      setLoading(false);
+    });
+
+    return () => subscription.unsubscribe();
+  }, []);
+
+  const checkAdminStatus = async () => {
+    try {
+      const { data: { user } } = await supabase.auth.getUser();
+      if (!user) return false;
+
+      const { data, error } = await supabase
+        .from('admin_roles')
+        .select('role')
+        .eq('user_id', user.id)
+        .maybeSingle();
+
+      const adminStatus = !error && data && ['admin', 'super_admin'].includes(data.role);
+      setIsAdmin(adminStatus);
+      return adminStatus;
+    } catch {
+      return false;
+    }
+  };
+
+  const signIn = async (email: string, password: string) => {
+    // Check if demo mode is enabled and this is the founder account
+    if (DEMO_MODE_ENABLED && email === FOUNDER_ACCOUNT.email && password === FOUNDER_ACCOUNT.password) {
+      // Try Supabase first
+      try {
+        const { data, error } = await supabase.auth.signInWithPassword({
+          email,
+          password,
+        });
+        
+        if (!error && data.user) {
+          await checkAdminStatus();
+          return { error: null };
+        }
+      } catch {
+        // Supabase not available
+      }
+
+      // Fallback to demo mode for founder account
+      const demoUser = {
+        id: FOUNDER_ACCOUNT.id,
+        email: FOUNDER_ACCOUNT.email,
+        user_metadata: FOUNDER_ACCOUNT.user_metadata,
+        email_confirmed_at: new Date().toISOString(),
+        created_at: new Date().toISOString(),
+      } as User;
+      
+      setUser(demoUser);
+      setIsAdmin(true);
+      
+      // Store in localStorage for persistence
+      localStorage.setItem('demo_user', JSON.stringify(demoUser));
+      
+      return { error: null };
+    }
+
+    // For other accounts, use Supabase
+    try {
+      const { data, error } = await supabase.auth.signInWithPassword({
+        email,
+        password,
+      });
+      
+      if (!error && data.user) {
+        await checkAdminStatus();
+      }
+      
+      return { error };
+    } catch (err) {
+      return { 
+        error: { 
+          message: 'Authentication service unavailable. Please try again later.' 
+        } 
+      };
+    }
+  };
+
+  const signUp = async (email: string, password: string, username: string, referralCode?: string) => {
+    try {
+      const { data, error } = await supabase.auth.signUp({
+        email,
+        password,
+        options: {
+          data: {
+            username,
+            referral_code: referralCode || null,
+          },
+        },
+      });
+
+      if (!error && data.user) {
+        // Create profile in profiles table with referral code
+        await supabase.from('profiles').insert({
+          id: data.user.id,
+          username,
+          email,
+          referred_by: referralCode || null,
+        });
+        
+        // If there's a referral code, track it
+        if (referralCode) {
+          // You can add logic here to reward the referrer
+          // For example, update their referral count or add rewards
+          console.log(`User registered with referral code: ${referralCode}`);
+        }
+      }
+
+      return { error };
+    } catch (err) {
+      return { 
+        error: { 
+          message: 'Registration service unavailable. Please try again later.' 
+        } 
+      };
+    }
+  };
+
+  const signOut = async () => {
+    localStorage.removeItem('demo_user');
+    setIsAdmin(false);
+    await supabase.auth.signOut();
+  };
+
+  // Check for demo user on mount
+  useEffect(() => {
+    const demoUser = localStorage.getItem('demo_user');
+    if (demoUser && !user) {
+      const parsedUser = JSON.parse(demoUser);
+      setUser(parsedUser);
+      setIsAdmin(true);
+    }
+  }, []);
+
+  return (
+    <AuthContext.Provider value={{ 
+      user, 
+      loading, 
+      isAdmin,
+      signIn, 
+      signUp, 
+      signOut,
+      checkAdminStatus 
+    }}>
+      {children}
+    </AuthContext.Provider>
+  );
+};