Merge branch 'feature/148-rattacher-enfant-capacite-max' into develop

Fix capacité max — lien rattacher enfant (#148).

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

@@ -238,6 +238,13 @@ class _AdminAmEditModalState extends State<AdminAmEditModal>
 
   int? _capaciteMax() => _parseIntField(_capaciteCtrl);
 
+  /// True si plus aucune place d'accueil (enfants ≥ capacité max).
+  bool get _capacityFull {
+    final max = _capaciteMax();
+    if (max == null) return false;
+    return _children.length >= max;
+  }
+
   int? _computedPlacesAvailable() => amExpectedPlacesAvailable(
         maxChildren: _capaciteMax(),
         childrenCount: _children.length,
@@ -466,7 +473,7 @@ class _AdminAmEditModalState extends State<AdminAmEditModal>
   }
 
   Future<void> _attachChild() async {
-    if (!mounted) return;
+    if (_capacityFull || !mounted) return;
     final selected = await AdminSelectEnfantModal.show(
       context,
       excludeIds: _children.map((c) => c.id).toSet(),
@@ -745,6 +752,7 @@ class _AdminAmEditModalState extends State<AdminAmEditModal>
 
   Widget _buildFooter() {
     final isChildrenTab = _tabCtrl.index == 2;
+    final canAttachChild = !_saving && !_capacityFull;
     return Row(
       children: [
         TextButton(
@@ -753,10 +761,15 @@ class _AdminAmEditModalState extends State<AdminAmEditModal>
         ),
         const Spacer(),
         if (isChildrenTab)
-          TextButton.icon(
-            onPressed: _attachChild,
-            icon: const Icon(Icons.link, size: 18),
-            label: const Text('Rattacher un enfant'),
+          Tooltip(
+            message: _capacityFull
+                ? 'Capacité maximale atteinte'
+                : 'Rattacher un enfant',
+            child: TextButton.icon(
+              onPressed: canAttachChild ? _attachChild : null,
+              icon: const Icon(Icons.link, size: 18),
+              label: const Text('Rattacher un enfant'),
+            ),
           ),
         if (isChildrenTab) const SizedBox(width: 12),
         ElevatedButton(