**Problem**: OAuth registration path (Google, Apple, Telegram) was missing the
email domain whitelist validation, causing trial subscriptions to be granted to
all users regardless of the whitelist configuration.
**Root Cause**: The previous commit (3417da2a) that implemented trial domain
whitelist only updated device/phone/email direct registration paths, but
missed the OAuth registration path in oAuthLoginGetTokenLogic.go.
**Solution**:
- Added email domain whitelist check to OAuth register() method
- Added isEmailDomainWhitelisted() helper function matching the pattern
used in other auth logic files
- Only activate trial if EnableTrial=true AND
(whitelist disabled OR email domain matches whitelist)
- Added email logging to trial subscription activation log
Affected flows:
- OAuth Google login with new user
- OAuth Apple login with new user
- OAuth Telegram login with new user
Co-Authored-By: claude-flow <ruv@ruv.net>
shanshanzhong
d586bbeabb