CAN's watch-scratchfile handler should listen to the SCRATCHFILE_FOUND event

So all scratchfiles found by CAN are watched for changes, the watch scratchfile handler should listen to the SCRATCHFILE_FOUND event.

Backlinks

• CAN should begin watching an existing scratchfile on startup
  • CAN fires a SCRATCHFILE_CREATED event. This is a similar but distinct event whic may repeat in multiple contexts if CAN allows multiple scratchfiles in the future - SCRATCHFILE_FOUND. CAN should fire a SCRATCHFILE_FOUND event when an existing scratchfile is found. CAN's watch-scratchfile handler should listen to the SCRATCHFILE_FOUND event.