The health check endpoint listens on a dedicated HTTP server.
By default, it is available at 0.0.0.0:9000/health. This can be configured using the --health-listen-address flag.
The results are cached for 3 seconds to avoid excessive calls.
The health check performs the following:
Checks the number of active listeners.
Validates each listener via WebSocket and QUIC dials, including TLS certificate verification.
When the signal connection is lost, we do not recreate the gRPC instance but instead cancel the context.
As a result, the worker is stopped but not restarted.
