fix(server): send sync route matching errors to the error handler

[RomainLanz]

Note

AI assistance was used to draft parts of the implementation, tests, and PR description.

Hey! 👋🏻

Without global middleware, a sync error raised while matching the route did not reach the app error handler. For example, a matcher cast that throws. The server logged it as fatal ("Exception raised by error handler") and the default error handler sent a 500. With global middleware, the same error reached the app error handler.

The cause is in the middleware Runner: it calls finalHandler().catch(errorHandler), so a sync error from the final handler skips the .catch and rejects the runner itself. With global middleware, the route finder runs inside a middleware's next(), so the error becomes a rejection of that middleware and the runner catches it.

The route finder now returns sync errors as a rejected promise, as it already does for E_ROUTE_NOT_FOUND.

New test: pass route matching errors to the error handler. It registers no global middleware and a route whose cast throws, and expects the response from the app error handler. It fails on 9.x with expected 422, got 500.