feat(#174): feed bulles AM + libellés statut / tri stable

Branche CartesFeed sur le TdB AM ; Vu / En attente de validation ;
préserve is_creator SSE et tri par cree_le pour limiter les écarts.

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

frontend/lib/models/carte_bulle.dart

@@ -80,6 +80,32 @@ class CarteBulle {
     this.modifieLe,
   });
 
+  CarteBulle copyWith({
+    CarteStatut? statut,
+    bool? isCreator,
+    String? lastRefuseComment,
+    DateTime? modifieLe,
+    Map<String, dynamic>? payload,
+  }) {
+    return CarteBulle(
+      id: id,
+      typeCode: typeCode,
+      titre: titre,
+      idPlacement: idPlacement,
+      idAbsence: idAbsence,
+      operation: operation,
+      statut: statut ?? this.statut,
+      payload: payload ?? this.payload,
+      purgeAt: purgeAt,
+      creePar: creePar,
+      isCreator: isCreator ?? this.isCreator,
+      responseMode: responseMode,
+      lastRefuseComment: lastRefuseComment ?? this.lastRefuseComment,
+      creeLe: creeLe,
+      modifieLe: modifieLe ?? this.modifieLe,
+    );
+  }
+
   String? get dateDebut => payload['date_debut']?.toString();
   String? get dateFin => payload['date_fin']?.toString();
   String? get motif => payload['motif']?.toString();