feat: add example components and system pages for UI showcase

- Introduced HeaderExample component for header display.
- Created StyleGuideOne, StyleGuideTwo, and StyleGuideThree components showcasing various UI elements and layouts.
- Added system pages: ComingSoon, Forbidden, Maintenance, and NotFound for better user experience during different states.
- Updated index.ts to export new components for easier access.

apps/web/src/apps/index.tsx

@@ -1,5 +1,6 @@
 import { lazy, Suspense } from 'react';
 import { BrowserRouter, Navigate, Route, Routes } from 'react-router-dom';
+import { NotFound, Forbidden, Maintenance, ComingSoon } from '@repo/ui';
 
 const AuthModule = lazy(() => import('./auth'));
 const AppModule = lazy(() => import('./modules'));
@@ -11,8 +12,10 @@ export default function App() {
         <Routes>
           <Route path="/auth/*" element={<AuthModule />} />
           <Route path="/app/*" element={<AppModule />} />
-          {/* <Route path="/404" element={<NotFoundPage />} />
-                <Route path="/403" element={<ForbiddenPage />} /> */}
+          <Route path="/404" element={<NotFound />} />
+          <Route path="/403" element={<Forbidden />} />
+          <Route path="/maintenance" element={<Maintenance />} />
+          <Route path="/coming-soon" element={<ComingSoon />} />
           <Route path="*" element={<Navigate to="/app" />} />
         </Routes>
       </Suspense>

apps/web/src/apps/modules/index.tsx

@@ -1,10 +1,13 @@
-import { DateServiceComponent } from '@repo/ui';
+import { DateServiceExample, StyleGuideOne, StyleGuideTree, StyleGuideTwo } from '@repo/ui';
 import { Route, Routes } from 'react-router-dom';
 
 export default function AppModule() {
   return (
     <Routes>
-      <Route path="/example/*" element={<DateServiceComponent />} />
+      <Route path="/example/*" element={<DateServiceExample />} />
+      <Route path="/guide-1/*" element={<StyleGuideOne />} />
+      <Route path="/guide-2/*" element={<StyleGuideTwo />} />
+      <Route path="/guide-3/*" element={<StyleGuideTree />} />
     </Routes>
   );
 }