Great idea.

As for naming convention, I have both my .gitignore and my FTP app set to ignore all "dev-*.php" files, so that they aren't committed to VCS nor uploaded to servers.
Alternatively, other utility tools often use underscore prefixes, for example one of them is: _ide_helper.php
(I avoid using dot-prefixed files for semi-sensitive things like this, just in case I accidentally ignore them because they're hidden-by-default.)