fix: avoid 400 error on invite code requirement check

docs/pow-server/invite-validate.php

@@ -13,6 +13,12 @@ if (!REQUIRE_INVITE_CODE) {
 }
 
 $input = json_decode(file_get_contents('php://input'), true);
+
+if (!empty($input['check'])) {
+    echo json_encode(['valid' => false, 'required' => true]);
+    exit;
+}
+
 $code = trim($input['code'] ?? '');
 
 if (!$code) {

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