fix(#146): densifier la liste et corriger l'affichage des responsables.

Les cartes compactes montrent plus d'enfants d'un coup ; le nom ne monopolise plus la largeur au détriment des infos.

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

frontend/lib/widgets/admin/common/admin_enfant_user_card.dart

@@ -35,6 +35,7 @@ class AdminEnfantUserCard extends StatelessWidget {
   final List<Widget> actions;
   final VoidCallback? onCardTap;
   final EdgeInsetsGeometry? margin;
+  final EdgeInsetsGeometry? contentPadding;
 
   const AdminEnfantUserCard({
     super.key,
@@ -44,6 +45,7 @@ class AdminEnfantUserCard extends StatelessWidget {
     this.actions = const [],
     this.onCardTap,
     this.margin,
+    this.contentPadding,
   });
 
   factory AdminEnfantUserCard.fromEnfant(
@@ -52,6 +54,7 @@ class AdminEnfantUserCard extends StatelessWidget {
     List<Widget> actions = const [],
     VoidCallback? onCardTap,
     EdgeInsetsGeometry? margin,
+    EdgeInsetsGeometry? contentPadding,
   }) {
     final parents = enfant.parentLinks
         .map((l) => l.parentName ?? 'Parent')
@@ -72,6 +75,7 @@ class AdminEnfantUserCard extends StatelessWidget {
       actions: actions,
       onCardTap: onCardTap,
       margin: margin,
+      contentPadding: contentPadding,
     );
   }
 
@@ -81,6 +85,7 @@ class AdminEnfantUserCard extends StatelessWidget {
     List<Widget> actions = const [],
     VoidCallback? onCardTap,
     EdgeInsetsGeometry? margin,
+    EdgeInsetsGeometry? contentPadding,
   }) {
     return AdminEnfantUserCard(
       title: child.fullName,
@@ -94,6 +99,7 @@ class AdminEnfantUserCard extends StatelessWidget {
       actions: actions,
       onCardTap: onCardTap,
       margin: margin,
+      contentPadding: contentPadding,
     );
   }
 
@@ -107,6 +113,7 @@ class AdminEnfantUserCard extends StatelessWidget {
       actions: actions,
       onCardTap: onCardTap,
       margin: margin,
+      contentPadding: contentPadding,
     );
   }
 }