feat(crm): align shared attachment payloads

internal/handler/api/v1/conversation_handler.go

@@ -764,13 +764,17 @@ func (h *ConversationHandler) ListAttachments(c *gin.Context) {
 	if !ok {
 		return
 	}
-	attachments, _, svcErr := h.messageSvc.ListAttachments(c.Request.Context(), accountID, conversation.ID, p.Offset, p.PerPage)
+	attachments, total, svcErr := h.messageSvc.ListAttachments(c.Request.Context(), accountID, conversation.ID, p.Offset, p.PerPage)
 	if svcErr != nil {
 		handleServiceError(c, svcErr)
 		return
 	}
 
-	c.JSON(http.StatusOK, gin.H{"payload": attachments})
+	payload := make([]any, 0, len(attachments))
+	for i := range attachments {
+		payload = append(payload, serializeAttachment(c.Request.Context(), h.conversationSvc.DB(), &attachments[i]))
+	}
+	c.JSON(http.StatusOK, gin.H{"meta": gin.H{"total_count": total}, "payload": payload})
 }
 
 // ToggleTyping toggles the typing status for an agent in a conversation.