The Windows app drops logs received over the tunnel, so this can be removed. It adds it's own sink to stderr.

We deliberately never cancel the tunnel ctx, due to the somewhat precarious teardown procedure. We do however cancel the updater ctx to ensure we don't tick network updates after shutdown, so we'll check for that here too.

I'm not seeing any value in this buffer, as we don't do any disk I/O - the pipe is entirely in-memory. With pings every 5 seconds and debug logs on, we produce around 150~ logs a minute, or about 35 kilobytes. The in-memory pipe can handle gigabytes a second. I think buffering would make sense were we relaying the logs to a terminal or a file, but that's not the case here.

Since only Error and above logs are flushed immediately, the alternative is adding the complexity of flushing the logs from the buffer periodically. One downside of this is that the macOS timestamps on the logs once they reach the Swift code aren't actually representative of the time the log was produced.