Refactor Notification Sending Logic to Use Goroutines

- Updated the Send method in NotificationHandler to send notifications asynchronously using goroutines, improving responsiveness and performance.
- Removed synchronous error handling for notification sending, allowing the API to return a success response immediately while processing the notification in the background.

internal/notification/handler.go

@@ -45,9 +45,7 @@ func (h *NotificationHandler) Send(c echo.Context) error {
 	}
 
 	// Send notification
-	if err := h.service.Send(c.Request().Context(), &req); err != nil {
+	go h.service.Send(c.Request().Context(), &req)
-		return response.InternalServerError(c, "Failed to send notification")
-	}
 
 	return response.Created(c, nil, "Notification sent successfully")
 }