An http probe of /v2/ said only that a port answered; design 51 asks the health check to call versions per seat and
probe the read side each minute, naming the program when it is down, from outside its process. registry_health asks
versions of each seat through the program's port, writes the read-side finding while it fails and clears it after.
Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig
