feat: Implement 4th demo - Gig Economy Madness with full blockchain integration

🚀 Major Features Added:
- ✅ 4th Demo: Gig Economy Madness (Micro-Task Marketplace) fully enabled
- ✅ Real blockchain integration with toggle between real/mock modes
- ✅ Live transaction tracking for all demo actions
- ✅ Dynamic Complete Demo button colors matching each demo theme
- ✅ Comprehensive Firebase tracking system with user analytics

🎨 UI/UX Improvements:
- ✅ Fixed RewardsSidebar crashes and React warnings
- ✅ Updated demo stats display from 'Completed' to 'tnx #' for clarity
- ✅ Proper purple/accent color scheme for gig economy demo
- ✅ Enhanced error handling and defensive programming

🔧 Technical Enhancements:
- ✅ Real Stellar blockchain transactions via useRealInitializeEscrow
- ✅ Complete transaction tracking with pending/success/failed states
- ✅ Firebase integration for demo completion and clap tracking
- ✅ User account creation, badge system, and leaderboard
- ✅ Environment variable validation fixes
- ✅ Type safety improvements and linting fixes

🎮 Demo Features:
- ✅ Task posting, accepting, completion, approval workflow
- ✅ Escrow integration with automatic fund release
- ✅ Role-based actions (client/worker/arbitrator)
- ✅ Category-based task filtering
- ✅ Progress tracking and completion requirements
- ✅ Confetti animations and success celebrations

📊 Analytics & Engagement:
- ✅ XP points and badge system
- ✅ Global leaderboard integration
- ✅ User progress tracking
- ✅ Demo completion statistics
- ✅ Social features (claps, feedback system)

This update makes the platform a complete, engaging, and robust Web3 learning experience!

Author: josegomez-dev

app/demos/page.tsx

@@ -90,7 +90,7 @@ const demos: Demo[] = [
       'Lightweight gig-board with escrow! Post tasks, browse opportunities, and manage micro-work with built-in escrow protection for both clients and workers.',
     icon: '/images/demos/economy.png',
     color: 'from-accent-500 to-accent-400',
-    isReady: false,
+    isReady: true,
     multiStakeholderRequired: false,
   },
 ];
@@ -294,7 +294,7 @@ const DemoSelector = ({
                             <div className='text-lg font-bold text-amber-400'>
                               {stats.completions}
                             </div>
-                            <div className='text-xs text-white/60'>Completed</div>
+                            <div className='text-xs text-white/60'>tnx #</div>
                           </div>
                           <div>
                             <button
@@ -477,7 +477,7 @@ function HomePageContent() {
   const { isConnected } = useGlobalWallet();
   const { isAuthenticated, user } = useAuth();
   const [activeDemo, setActiveDemo] = useState('hello-milestone');
-  const { submitFeedback } = useDemoStats();
+  const { submitFeedback, markDemoComplete } = useDemoStats();
 
   const [walletSidebarOpen, setWalletSidebarOpen] = useState(false);
   const [walletExpanded, setWalletExpanded] = useState(false);
@@ -587,7 +587,14 @@ function HomePageContent() {
   };
 
   // Handle demo completion and show feedback modal
-  const handleDemoComplete = (demoId: string, demoName: string, completionTime: number = 5) => {
+  const handleDemoComplete = async (demoId: string, demoName: string, completionTime: number = 5) => {
+    // Mark demo as complete in Firebase
+    try {
+      await markDemoComplete(demoId, demoName, completionTime);
+    } catch (error) {
+      console.error('Failed to mark demo as complete:', error);
+    }
+    
     setFeedbackDemoData({
       demoId,
       demoName,