Redirect invite logins to wiki, regular logins to /members

Invite tokens now include a redirect claim so the verify endpoint
can distinguish them from regular login tokens. Only invite links
redirect to wiki.ghostguild.org; normal logins go to /members.

server/api/admin/members/invite.post.js

@@ -31,7 +31,7 @@ export default defineEventHandler(async (event) => {
     try {
       // Generate 48-hour magic login token (same format as login.post.js)
       const token = jwt.sign(
-        { memberId: member._id },
+        { memberId: member._id, redirect: 'wiki' },
         config.jwtSecret,
         { expiresIn: '48h' }
       )