fix(#138): enrichir les noms des responsables sur GET enfant.

GET /enfants/:id ne joint pas parent.user ; on complète les noms via
GET parent pour l'affichage des liens (ex. ouverture depuis la fiche AM).

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

frontend/lib/models/enfant_admin_model.dart

@@ -37,6 +37,34 @@ class EnfantAdminModel {
     return '$fn $ln';
   }
 
+  EnfantAdminModel copyWith({
+    String? id,
+    String? firstName,
+    String? lastName,
+    String? gender,
+    String? birthDate,
+    String? dueDate,
+    String? status,
+    String? photoUrl,
+    bool? consentPhoto,
+    bool? isMultiple,
+    List<EnfantParentLink>? parentLinks,
+  }) {
+    return EnfantAdminModel(
+      id: id ?? this.id,
+      firstName: firstName ?? this.firstName,
+      lastName: lastName ?? this.lastName,
+      gender: gender ?? this.gender,
+      birthDate: birthDate ?? this.birthDate,
+      dueDate: dueDate ?? this.dueDate,
+      status: status ?? this.status,
+      photoUrl: photoUrl ?? this.photoUrl,
+      consentPhoto: consentPhoto ?? this.consentPhoto,
+      isMultiple: isMultiple ?? this.isMultiple,
+      parentLinks: parentLinks ?? this.parentLinks,
+    );
+  }
+
   factory EnfantAdminModel.fromJson(Map<String, dynamic> json) {
     final linksRaw = json['parentLinks'] as List?;
     final links = <EnfantParentLink>[];
@@ -106,6 +134,13 @@ class EnfantParentLink {
 
   EnfantParentLink({required this.parentId, this.parentName});
 
+  EnfantParentLink copyWith({String? parentId, String? parentName}) {
+    return EnfantParentLink(
+      parentId: parentId ?? this.parentId,
+      parentName: parentName ?? this.parentName,
+    );
+  }
+
   factory EnfantParentLink.fromJson(Map<String, dynamic> json) {
     final parentId =
         (json['parentId'] ?? json['id_parent'] ?? '').toString();
@@ -116,6 +151,12 @@ class EnfantParentLink {
       if (user is Map<String, dynamic>) {
         final u = AppUser.fromJson(user);
         name = u.fullName.isNotEmpty ? u.fullName : u.email;
+      } else {
+        // Parfois le parent est aplati (prenom/nom) sans nested user.
+        final prenom = (parent['prenom'] ?? parent['first_name'] ?? '').toString().trim();
+        final nom = (parent['nom'] ?? parent['last_name'] ?? '').toString().trim();
+        final flat = '$prenom $nom'.trim();
+        if (flat.isNotEmpty) name = flat;
       }
     }
     return EnfantParentLink(

frontend/lib/services/user_service.dart

@@ -460,7 +460,40 @@ class UserService {
     if (response.statusCode != 200) {
       throw Exception(_extractErrorMessage(response.body, 'Erreur chargement enfant'));
     }
-    return EnfantAdminModel.fromJson(jsonDecode(response.body) as Map<String, dynamic>);
+    final enfant = EnfantAdminModel.fromJson(
+      jsonDecode(response.body) as Map<String, dynamic>,
+    );
+    // GET /enfants/:id ne joint pas toujours parent.user → noms manquants.
+    return enrichEnfantParentNames(enfant);
+  }
+
+  /// Complète [parentName] via GET parent quand l'API n'a pas fourni le nested user.
+  static Future<EnfantAdminModel> enrichEnfantParentNames(
+    EnfantAdminModel enfant,
+  ) async {
+    final links = enfant.parentLinks;
+    if (links.isEmpty) return enfant;
+    if (links.every((l) => (l.parentName ?? '').trim().isNotEmpty)) {
+      return enfant;
+    }
+
+    final enriched = await Future.wait(
+      links.map((link) async {
+        if ((link.parentName ?? '').trim().isNotEmpty) return link;
+        final id = link.parentId.trim();
+        if (id.isEmpty) return link;
+        try {
+          final parent = await getParent(id);
+          final name = parent.user.fullName.trim();
+          if (name.isEmpty) return link;
+          return link.copyWith(parentName: name);
+        } catch (_) {
+          return link;
+        }
+      }),
+    );
+
+    return enfant.copyWith(parentLinks: enriched);
   }
 
   static Future<EnfantAdminModel> updateEnfant({
@@ -475,7 +508,10 @@ class UserService {
     if (response.statusCode != 200) {
       throw Exception(_extractErrorMessage(response.body, 'Erreur mise à jour enfant'));
     }
-    return EnfantAdminModel.fromJson(jsonDecode(response.body) as Map<String, dynamic>);
+    final enfant = EnfantAdminModel.fromJson(
+      jsonDecode(response.body) as Map<String, dynamic>,
+    );
+    return enrichEnfantParentNames(enfant);
   }
 
   static Future<void> deleteEnfant(String enfantId) async {