feat(nav): visible Admin Panel link in navbar for admins

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/layout/Navbar.tsx

@@ -108,6 +108,14 @@ export function Navbar({ user }: { user?: NavUser | null }) {
             {t("pricing")}
           </Link>
           <NavbarLearnDropdown items={learnItems} label={t("learn")} />
+          {user?.isAdmin && (
+            <Link
+              href="/admin"
+              className="rounded-md px-3 py-2 text-sm font-semibold text-indigo-600 transition-colors hover:bg-indigo-50 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-blue-600 focus-visible:ring-offset-2"
+            >
+              {t("menuAdminPanel")}
+            </Link>
+          )}
         </nav>
 
         {/* Right-side actions */}