IGrpcService.handleRequest(request: Request): Promise<Response>
Handles an incoming RPC request directly.
Called by the kernel terminal handler after the middleware pipeline has
run and IGrpcService.claims has accepted the path; also usable
directly by tests and advanced scenarios.
Returns a 404 response for a path this service claims but for which no
procedure is registered. It never returns null, which is why
IGrpcService.claims exists.
request: Request
The native fetch request
Promise<Response>
The gRPC/Connect response