feat: add landing homepage with hero section and feature showcase

Create new HomePage component with:
- Hero section with CTAs for registration and login
- Features showcase highlighting WebRTC, matching, chat, security
- How it works section with 3-step process
- CTA section and footer with links
- Responsive design with gradient backgrounds

Update routing to show HomePage at / instead of redirecting to /events

frontend/src/App.jsx

@@ -1,5 +1,6 @@
 import { BrowserRouter, Routes, Route, Navigate } from 'react-router-dom';
 import { AuthProvider, useAuth } from './contexts/AuthContext';
+import HomePage from './pages/HomePage';
 import LoginPage from './pages/LoginPage';
 import RegisterPage from './pages/RegisterPage';
 import VerifyEmailPage from './pages/VerifyEmailPage';
@@ -160,7 +161,7 @@ function App() {
             }
           />
 
-          {/* Public Profile - must be before default redirect */}
+          {/* Public Profile - must be before home route */}
           <Route
             path="/:username"
             element={
@@ -170,8 +171,8 @@ function App() {
             }
           />
 
-          {/* Default redirect */}
-          <Route path="/" element={<Navigate to="/events" replace />} />
+          {/* Home Page */}
+          <Route path="/" element={<HomePage />} />
         </Routes>
       </AuthProvider>
     </BrowserRouter>