fix: improved guard routing and optimized user data loading

src/app/guards/redirect-if-authenticated.guard.ts

@@ -24,6 +24,7 @@ export class RedirectIfAuthenticatedGuard {
     return this.authService.checkAuthUser().pipe(
       map((isAuthenticated) => {
         if (isAuthenticated) {
+          this.router.navigate(['/summary']);
           return false;
         }
         return true;

src/app/shared/components/header/header.component.ts

@@ -6,6 +6,7 @@ import { TranslateModule } from '@ngx-translate/core';
 import { FirebaseService } from '../../../services/firebase.service';
 import { AuthService } from '../../../services/auth.service';
 import { ApiService } from '../../../services/api.service';
+import { catchError, of, switchMap } from 'rxjs';
 
 @Component({
   selector: 'app-header',
@@ -33,20 +34,21 @@ export class HeaderComponent {
   }
 
   /**
-   * Loads the current user data by calling the getCurrentUserId method of the AuthService.
+   * Loads the current user data and sets it to the `currentUser` property.
    */
   loadCurrentUser(): void {
-    this.authService.getCurrentUserId().subscribe((userId) => {
-      if (userId) {
-        this.apiService.getUserById(userId).subscribe(
-          (userData) => {
-            this.currentUser = userData;
-          },
-          () => {
-            this.currentUser = {};
-          }
-        );
-      }
+    this.authService
+      .getCurrentUserId()
+      .pipe(
+        switchMap((userId) => {
+          if (!userId) return of(null);
+          return this.apiService
+            .getUserById(userId)
+            .pipe(catchError(() => of(null)));
+        })
+      )
+      .subscribe((userData) => {
+        this.currentUser = userData || {};
       });
   }