b95f552ed2
When ADMIN_USERNAME/ADMIN_PASSWORD env vars are not configured, settings values are None. Python's `None == None` evaluates to True, so any login request omitting those form fields was authenticated as admin — creating a phantom 'None@local.docuelevate' profile with admin rights and business plan. Guard the admin credential check to require both values to be truthy (non-None, non-empty) before attempting the comparison. Adds three regression tests covering: both None, both empty-string, and only password None scenarios. Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>