Implement AuthGuard for route protection, integrate authorization checks into particles route, and simplify HeaderComponent access logic. Remove redundant debug logging in auth.service.ts.

frontend/src/app/pages/header/header/header.component.html

@@ -141,11 +141,9 @@
             <li class="nav_li">
               <a [id]="getCurrentPageId(['particles'])"
                  class="nav_link fake_link" [ngClass]="active">Special</a>
-              @if (hasAccess(['SCOPE_head_mod'])) {
-                <ul class="dropdown">
-                  <li class="nav_li"><a class="nav_link2" [routerLink]="['/particles']">Particles</a></li>
-                </ul>
-              }
+              <ul class="dropdown">
+                <li class="nav_li"><a class="nav_link2" [routerLink]="['/particles']">Particles</a></li>
+              </ul>
             </li>
           }
           @if (!isAuthenticated) {