Phil Skentelbery
43bfce3913
Prevent duplicate registrations for the same exchange: - Check for existing participant with same email (case-insensitive) - Show friendly message if already registered - Offer link to request new magic link for access - Allow same email to register for different exchanges - Comprehensive test suite with 4 tests All tests passing (90 total), 91% coverage maintained. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>