fix: stop importing existing GWS users into Pulumi state

The GWS provider validates email types during import, but GWS itself
returns empty types for primary/alias emails. This causes unrecoverable
validation errors on every new user import. Instead, skip managing
existing users entirely and let group memberships be created directly.

Also marks den as existingGWSUser.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/config/users.ts

@@ -358,6 +358,7 @@ export const MEMBERS: readonly Member[] = [
     firstName: 'Den',
     lastName: 'Delimarsky',
     googleEmailPrefix: 'den',
+    existingGWSUser: true,
     memberOf: [
       ROLE_IDS.AUTH_MAINTAINERS,
       ROLE_IDS.CORE_MAINTAINERS,