Add inscription button in navbar for non-authenticated users

- Desktop: yellow "Inscription" button next to login icon (hidden on mobile)
- Mobile menu: yellow "Inscription" block after "Connexion" link
- Registration was already functional at /inscription, just missing from navbar

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

templates/base.html.twig

@@ -110,6 +110,7 @@
                                 <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M16 7a4 4 0 11-8 0 4 4 0 018 0zM12 14a7 7 0 00-7 7h14a7 7 0 00-7-7z"/></svg>
                             </a>
                         {% else %}
+                            <a href="{{ path('app_register') }}" class="hidden lg:inline-flex px-3 py-1.5 border-2 border-gray-900 bg-[#fabf04] text-gray-900 text-xs font-black uppercase tracking-widest hover:bg-yellow-500 transition-all items-center">Inscription</a>
                             <a href="{{ path('app_login') }}" class="p-2 border-2 border-gray-900 bg-white text-gray-900 hover:bg-gray-900 hover:text-white transition-all flex items-center justify-center" aria-label="Connexion">
                                 <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M16 7a4 4 0 11-8 0 4 4 0 018 0zM12 14a7 7 0 00-7 7h14a7 7 0 00-7-7z"/></svg>
                             </a>
@@ -135,6 +136,7 @@
                     <a href="{{ path('app_account') }}" class="block p-3 border-2 border-transparent hover:border-gray-900 hover:bg-gray-50" role="menuitem">Mon espace</a>
                 {% else %}
                     <a href="{{ path('app_login') }}" class="block p-3 border-2 border-transparent hover:border-gray-900 hover:bg-gray-50" role="menuitem">Connexion</a>
+                    <a href="{{ path('app_register') }}" class="block p-3 border-2 border-gray-900 bg-[#fabf04] text-center" role="menuitem">Inscription</a>
                 {% endif %}
             </div>
         </div>