Admin user authentication treats email addresses as case-sensitive

[antonioribeiro]

Description

Twill's admin authentication appears to treat email addresses as case-sensitive, causing login failures when users enter their email in a different case than how it was originally stored.

Steps to reproduce

1. Create a Twill admin user with email User@example.com
2. Attempt to log in with user@example.com
3. Login fails

Expected result

Email addresses should be treated as case-insensitive for authentication. A user registered as John.Smith@example.com should be able to log in with john.smith@example.com.

• RFC 5321 recommends treating email addresses as case-insensitive for practical purposes
• All major email providers (Gmail, Outlook, Yahoo) treat addresses as case-insensitive
• Mobile devices often auto-capitalize the first letter, causing unexpected login failures
• This is a common UX friction point that leads to support requests

Actual result

Login fails when the email case doesn't exactly match the stored value.

Versions

• Twill version: 3.5.2
• Laravel version: 11
• PHP version: 8.3