Many model crashes are masked behind "An existing connection was forcibly closed by the remote host"
This captures that common error message and wires in any detected errors from the log.
This also adds the deepseek context shift error to the known errors we capture.
This should resolve a number of memory leak and stability defects by allowing
us to isolate llama.cpp in a separate process and shutdown when idle, and
gracefully restart if it has problems. This also serves as a first step to be
able to run multiple copies to support multiple models concurrently.
