add initial Angular components, services, and routing setup

client/src/app/guards/guest-only/guest-only.guard.ts

@@ -0,0 +1,13 @@
+import { inject } from '@angular/core';
+import { Router, UrlTree, CanActivateFn, CanMatchFn } from '@angular/router';
+import { AuthService } from '../../services/auth/auth.service';
+
+function redirectIfLoggedIn(): boolean | UrlTree {
+  const authService = inject(AuthService);
+  const router = inject(Router);
+  // Si déjà connecté -> redirige vers /home
+  return authService.isLoggedIn() ? router.parseUrl('/home') : true;
+}
+
+export const guestOnlyCanMatch: CanMatchFn = () => redirectIfLoggedIn();
+export const guestOnlyCanActivate: CanActivateFn = () => redirectIfLoggedIn();