Fourth off the port list. Users do not open devtools, and "it did not work"
with nothing to read is where a bug report dies -- especially on a rented box
behind a tunnel, where the terminal that has the answer is not on this desk.
Read from ComfyUI's own log FILE rather than from a buffer in this process.
v4 kept both and its own comment says why the file is the half that matters: a
crash and restart empties an in-memory buffer, and the lines from before the
crash are exactly the ones worth reading. So this is the smaller half and the
more useful one.
Three things the panel refuses to do, each because of what a log is FOR:
* It does not redraw while text is being selected. Copying a stack trace is the
one thing anybody opens a log to do, and a panel that repaints under the drag
makes it impossible.
* It keeps the last lines when the server stops answering. The most interesting
thing a log can say is that ComfyUI just died, and replacing the lines from
just before it went with the error that says it is gone throws away the only
evidence of why.
* No log file is an ANSWER, with the reason and where to look instead. An empty
list reads as a quiet log, and the difference matters precisely when somebody
opened the panel because something else already broke.
