fix(#98): corriger la compatibilité Flutter du bouton image

Supprime le paramètre mouseCursor de TextButton.styleFrom (non supporté par la version Flutter du projet) et conserve le curseur pointeur via MouseRegion.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/lib/widgets/image_button.dart

@@ -29,12 +29,13 @@ class ImageButton extends StatelessWidget {
       child: Semantics(
         button: true,
         label: text,
+        child: MouseRegion(
+          cursor: SystemMouseCursors.click,
           child: TextButton(
             onPressed: onPressed,
             style: TextButton.styleFrom(
               padding: EdgeInsets.zero,
               tapTargetSize: MaterialTapTargetSize.shrinkWrap,
-            mouseCursor: SystemMouseCursors.click,
               shape:
                   const RoundedRectangleBorder(borderRadius: BorderRadius.zero),
             ),
@@ -58,6 +59,7 @@ class ImageButton extends StatelessWidget {
             ),
           ),
         ),
+      ),
     );
   }
 }