feat(#93): optimiser l’affichage Parents/AM avec modale de détails

Intègre un bandeau unique (onglets à gauche, recherche/filtre en pilule, bouton Ajouter à droite) et compacte les cartes Parents/AM avec ouverture d’une modale complète sur Modifier (croix, actions Modifier/Supprimer).

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

frontend/lib/widgets/admin/dashboard_admin.dart

@@ -136,39 +136,91 @@ class DashboardAppBarAdmin extends StatelessWidget
 class DashboardUserManagementSubBar extends StatelessWidget {
   final int selectedSubIndex;
   final ValueChanged<int> onSubTabChange;
+  final TextEditingController searchController;
+  final String searchHint;
+  final Widget? filterControl;
+  final VoidCallback? onAddPressed;
+  final String addLabel;
 
   const DashboardUserManagementSubBar({
     Key? key,
     required this.selectedSubIndex,
     required this.onSubTabChange,
+    required this.searchController,
+    required this.searchHint,
+    this.filterControl,
+    this.onAddPressed,
+    this.addLabel = '+ Ajouter',
   }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return Container(
-      height: 48,
+      height: 56,
       decoration: BoxDecoration(
         color: Colors.grey.shade100,
         border: Border(bottom: BorderSide(color: Colors.grey.shade300)),
       ),
       padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 6),
-      child: Center(
-        child: Row(
-          mainAxisSize: MainAxisSize.min,
-          children: [
-            _buildSubNavItem(context, 'Gestionnaires', 0),
-            const SizedBox(width: 16),
-            _buildSubNavItem(context, 'Parents', 1),
-            const SizedBox(width: 16),
-            _buildSubNavItem(context, 'Assistantes maternelles', 2),
-            const SizedBox(width: 16),
-            _buildSubNavItem(context, 'Administrateurs', 3),
+      child: Row(
+        children: [
+          _buildSubNavItem(context, 'Gestionnaires', 0),
+          const SizedBox(width: 12),
+          _buildSubNavItem(context, 'Parents', 1),
+          const SizedBox(width: 12),
+          _buildSubNavItem(context, 'Assistantes maternelles', 2),
+          const SizedBox(width: 12),
+          _buildSubNavItem(context, 'Administrateurs', 3),
+          const SizedBox(width: 36),
+          _pillField(
+            width: 320,
+            child: TextField(
+              controller: searchController,
+              decoration: InputDecoration(
+                hintText: searchHint,
+                prefixIcon: const Icon(Icons.search, size: 18),
+                border: InputBorder.none,
+                isDense: true,
+                contentPadding: const EdgeInsets.symmetric(
+                  horizontal: 10,
+                  vertical: 8,
+                ),
+              ),
+            ),
+          ),
+          if (filterControl != null) ...[
+            const SizedBox(width: 12),
+            _pillField(width: 150, child: filterControl!),
           ],
-        ),
+          const Spacer(),
+          _buildAddButton(),
+        ],
       ),
     );
   }
 
+  Widget _pillField({required double width, required Widget child}) {
+    return Container(
+      width: width,
+      height: 34,
+      decoration: BoxDecoration(
+        color: Colors.white,
+        borderRadius: BorderRadius.circular(18),
+        border: Border.all(color: Colors.black26),
+      ),
+      alignment: Alignment.centerLeft,
+      child: child,
+    );
+  }
+
+  Widget _buildAddButton() {
+    return ElevatedButton.icon(
+      onPressed: onAddPressed,
+      icon: const Icon(Icons.add),
+      label: Text(addLabel),
+    );
+  }
+
   Widget _buildSubNavItem(BuildContext context, String title, int index) {
     final bool isActive = index == selectedSubIndex;
     return InkWell(