Adds a dedicated EMAIL_ADDRESS entry to the ScalarTypes enum and maps it to `string` in ScalarTypeRuntimeTypeMapping. Mirrors the IP_ADDRESS addition from #559. Lets Coop tag a schema field as an email address so integrations (NCMEC today; potentially others later) can pull it via schema-field role metadata instead of accepting any STRING-typed field. Format validation lives at the field-value level, not in this type. Required before #840 can switch the `email` field role from STRING to EMAIL_ADDRESS. Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>