Add TypeScript types for routes

**Feature request**
It would be great to have export for helpers.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_export` with default `false`.

Start by locating the route helpers, TypeScript type definitions, and configuration parsing in the repository; no file or test is named in the issue. Clarify whether the goal is exported route helpers and types, the `enable_export` option, or both, then verify that the option defaults to `false` and the requested exports are available.

Written by the indexing model from the issue text.