fix(canvas): 资源引用 - 校验递归素材并修复断链

backend/internal/kernel/errors.go

@@ -9,6 +9,7 @@ type AppError struct {
 	Message   string
 	Retryable bool
 	Cause     error
+	Details   map[string]any
 }
 
 func (e *AppError) Error() string {