Both were dead/incomplete: POST /api/user/key called a nonexistent
User.addSSHkey, and the invite flow (POST /api/user/invite, User.invite,
User.addByInvite, InviteToken) had no consumer or UI. Drop the routes, the
InviteToken model, and the per-backing invite methods.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>