The health check the backend runs against this instance after registration.
Not optional and not disable-able: self-registration happens at onBootstrap,
which runs before the socket is bound, so the instance is advertised for a
short window before it can serve. That window is harmless only because the
backend marks a newly registered service critical until its first check
passes and every read filters on passing instances — which makes the check
load-bearing rather than a convenience.
readonly
httpPath: string
HTTP path the backend polls, appended to this instance's origin.
readonly
intervalSeconds: number
Seconds between checks.
readonly
deregisterAfterSeconds: number
Seconds a critical service survives before the backend removes it.