Kura now serves HTTP and REAPI gRPC on a single listener

Kura’s Helm chart now serves both the HTTP cache API and the REAPI gRPC surface on a single listener. This removes the separate gRPC listener and port, so you can configure one cache endpoint (port 4000 by default, or 4443 with TLS). Self-hosters should drop KURA_GRPC_PORT and KURA_GRPC_TLS_* settings and point gRPC clients at the same cache port. The chart’s service.grpcPort value has been removed and now requires a co-hosted Kura image.