feat(settings): align assignable agents payloads

internal/handler/api/v1/assignable_agent_handler.go

@@ -80,5 +80,39 @@ func (h *AssignableAgentHandler) List(c *gin.Context) {
 		return
 	}
 
-	response.OK(c, agents)
+	c.JSON(http.StatusOK, gin.H{"payload": serializeAssignableAgents(accountID, agents)})
+}
+
+func serializeAssignableAgents(accountID uint, agents []service.AssignableAgentDTO) []map[string]any {
+	payload := make([]map[string]any, 0, len(agents))
+	for i := range agents {
+		agent := agents[i]
+		availableName := agent.DisplayName
+		if availableName == "" {
+			availableName = agent.Name
+		}
+		provider := agent.Provider
+		if provider == "" {
+			provider = "email"
+		}
+		customRoleID := any(nil)
+		if agent.CustomRoleID != 0 {
+			customRoleID = agent.CustomRoleID
+		}
+		payload = append(payload, map[string]any{
+			"id":                  agent.ID,
+			"account_id":          accountID,
+			"availability_status": agent.AvailabilityStatus,
+			"auto_offline":        agent.AutoOffline,
+			"confirmed":           agent.Confirmed,
+			"email":               agent.Email,
+			"provider":            provider,
+			"available_name":      availableName,
+			"name":                agent.Name,
+			"role":                agent.Role,
+			"thumbnail":           agent.AvatarURL,
+			"custom_role_id":      customRoleID,
+		})
+	}
+	return payload
 }