fix: avoid 400 error on invite code requirement check

js/components/auth-modal.js

@@ -30,7 +30,7 @@ class AuthModal extends HTMLElement {
             const res = await fetch(`${POW_SERVER}/invite/validate`, {
                 method: 'POST',
                 headers: { 'Content-Type': 'application/json' },
-                body: JSON.stringify({ code: '' })
+                body: JSON.stringify({ check: true })
             })
             const data = await res.json()
             this.requireInviteCode = !data.valid