RequestCast 1.7.1

A settings file that cannot be written no longer costs you the tool update it was trying
to record.

Tool updates survive a read-only settings file. When RequestCast installs or updates
yt-dlp or Deno, it writes down where the new copy landed. If the settings file cannot be
written — a service confined to a few writable paths, a portable copy on read-only media —
that write failed loudly enough to take the update with it: the background updater thread
died the first time it succeeded at anything, so yt-dlp was never checked again for as long
as the program stayed running, and the "check for updates now" button returned an error
after having updated the tools. Installing a missing tool mid-download failed the same way,
reporting that the tool could not be installed when it just had been.

The tool is installed either way, and RequestCast looks in its own tools folder before
PATH, so an unwritable settings file now costs nothing but the note of where the tool went.