Add visibility toggle for picks features and rename Mes choix to Mes picks

- Renamed 'Mes choix' to 'Mes picks' across all pages and JavaScript files
- Added visibility toggle in control panel (Réglages > Visibilité) to control:
  - Display of 'Mes picks' button in navigation
  - Display of 'Bon picks' column in user statistics
- Combined both visibility options into single toggle for simplicity
- Added backend API endpoints for visibility configuration
- Implemented localStorage caching for instant visibility updates
- Fixed flash of content issues when navigating between pages
- Updated stats endpoint to calculate correct picks on-the-fly from current winners
- Renamed 'Bonnes réponses' to 'Bon picks' in user statistics table

public/control.html

@@ -43,7 +43,7 @@
         <a href="movies.html" class="nav-link btn btn-outline-light me-2">Films</a>
         <a href="checklist.html" class="nav-link btn btn-outline-light me-2">Checklist</a>
         <a href="user-stat.html" class="nav-link btn btn-outline-light me-2">Statistiques</a>
-        <a href="picks.html" class="nav-link btn btn-outline-light me-2">Mes choix</a>
+        <a href="picks.html" class="nav-link btn btn-outline-light me-2" id="nav-link-picks" style="display: none;">Mes picks</a>
         <a href="control.html" class="nav-link btn btn-warning me-2">Admin</a>
       </div>
       <div class="d-flex ms-auto mt-2 mt-lg-0 align-items-center">
@@ -136,6 +136,11 @@
               Points
             </button>
           </li>
+          <li class="nav-item" role="presentation">
+            <button class="nav-link" id="admin-settings-subtab-visibility" data-bs-toggle="tab" data-bs-target="#admin-settings-pane-visibility" type="button" role="tab" aria-controls="admin-settings-pane-visibility" aria-selected="false">
+              Visibilité
+            </button>
+          </li>
         </ul>
 
         <div class="tab-content pt-3">
@@ -245,6 +250,32 @@
               </div>
             </div>
           </div>
+
+          <!-- Visibility settings -->
+          <div class="tab-pane fade" id="admin-settings-pane-visibility" role="tabpanel" aria-labelledby="admin-settings-subtab-visibility" tabindex="0">
+            <div class="border rounded p-3 bg-light">
+              <div class="text-muted small mb-3">
+                Contrôle la visibilité de certains éléments dans l'interface.
+              </div>
+
+              <div id="visibility-config-alert" class="alert d-none" role="alert"></div>
+
+              <div class="form-check">
+                <input class="form-check-input" type="checkbox" id="visibility-show-picks-features">
+                <label class="form-check-label" for="visibility-show-picks-features">
+                  Afficher les fonctionnalités "Picks"
+                </label>
+                <div class="form-text">Contrôle l'affichage du bouton "Mes picks" dans la navigation et de la colonne "Bon picks" dans les statistiques.</div>
+              </div>
+
+              <div class="mt-3">
+                <div class="d-flex gap-2">
+                  <button type="button" id="visibility-config-reload" class="btn btn-outline-secondary">Recharger</button>
+                  <button type="button" id="visibility-config-save" class="btn btn-warning">Enregistrer</button>
+                </div>
+              </div>
+            </div>
+          </div>
         </div>
       </div>
     </div>