Introduce a new health check endpoint at `/api/health`. This endpoint
returns a JSON response indicating the server's status and configuration
details, such as the port, data path, and configured URLs for external
services.
This change also refactors the application setup by:
- Creating a `lib.rs` file to house the `create_router` function, making
it
reusable for both the main application and integration tests.
- Moving configuration loading logic into `main.rs` and passing it as a
shared state (`Arc<Config>`) to the router.
- Adding a unit test (`health_test.rs`) to verify the functionality of
the
health check endpoint.
- Updating `Cargo.toml` and `Cargo.lock` to include the `tower`
dependency,
which is used for testing.
Brummel