Enhanced error handling for Facebook Login to provide clearer messages when
the service is unavailable. Added comprehensive setup documentation for
configuring Facebook OAuth properly.
Changes:
- Improved error messages in Facebook SDK for unavailable service
- Updated login page to display specific error messages to users
- Added FACEBOOK_LOGIN_SETUP.md with step-by-step configuration guide
- Documented alternatives (email/Google login) while Facebook is being configured
This addresses the "Fonctionnalité indisponible" error users are seeing
when attempting to use Facebook Login.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
