West Coast Pest /pest login hotfix

Overwrite these files into:
/public_html/pest/api/

Files:
- helpers.php
- login.php

What changed:
- removed fragile dependency on information_schema for column checks
- removed direct roles join from login
- role name is now resolved safely only if the roles table supports it
- login now returns JSON error_detail on server-side failure inside /pest only
- requireAuth is hardened for the same reason

After upload:
1. Hard refresh /pest/attendance/
2. Try login again
3. If it still fails, send the exact JSON shown on screen
