ZTNET: any logged-in user can lock out other accounts, including admins

ZTNET is a ZeroTier web UI for private controllers with multiuser and organization support. Prior to 0.8.0, any authenticated low-privilege user can permanently deactivate another account, including an administrator, through POST /api/auth/user/invalidateUser. In src/pages/api/auth/user/invalidateUser.ts, getServerSession checks only that a session exists and does not compare session.user.id with the client-supplied userId. Supplying a victim's userId and a deviceId for which no matching pair exists in UserDevice makes the handler set the target account's isActive to false. Login is then refused by src/server/auth.ts with account-expired. An attacker needs only a normal authenticated account and the victim's user ID, which may be obtainable from member lists, UI responses, logs, or other application metadata. This can lock administrators out, disrupt organization management, and deny access to any targeted user. This issue is fixed in version 0.8.0.