fix(auth): enable local registration for OSS invitations (#2460)

Co-authored-by: dadachann <185672915+dadachann@users.noreply.github.com>

web/src/app/infra/http/BackendClient.ts

@@ -1181,6 +1181,7 @@ export class BackendClient extends BaseHttpClient {
   public getAccountInfo(): Promise<{
     initialized: boolean;
     authenticated_invitation_acceptance_enabled?: boolean;
+    invitation_registration_enabled?: boolean;
     password_login_enabled?: boolean;
     space_login_enabled?: boolean;
   }> {

web/src/app/invitations/accept/page.tsx

@@ -91,7 +91,9 @@ export default function AcceptInvitationPage() {
   const [errorMessage, setErrorMessage] = useState('');
   const [password, setPassword] = useState('');
   const [confirmPassword, setConfirmPassword] = useState('');
-  const [passwordRegistrationEnabled, setPasswordRegistrationEnabled] =
+  const [invitationRegistrationEnabled, setInvitationRegistrationEnabled] =
+    useState(false);
+  const [invitationCapabilitiesLoaded, setInvitationCapabilitiesLoaded] =
     useState(false);
   const [
     authenticatedInvitationAcceptanceEnabled,
@@ -116,12 +118,16 @@ export default function AcceptInvitationPage() {
     backendClient
       .getAccountInfo()
       .then((info) => {
-        setPasswordRegistrationEnabled(info.password_login_enabled !== false);
+        setInvitationRegistrationEnabled(
+          info.invitation_registration_enabled ??
+            info.password_login_enabled !== false,
+        );
         setAuthenticatedInvitationAcceptanceEnabled(
           info.authenticated_invitation_acceptance_enabled === true,
         );
       })
-      .catch(() => setPasswordRegistrationEnabled(false));
+      .catch(() => setInvitationRegistrationEnabled(false))
+      .finally(() => setInvitationCapabilitiesLoaded(true));
     if (!invitationToken) {
       setErrorMessage(t('workspace.invitationMissing'));
       setStatus('error');
@@ -311,7 +317,11 @@ export default function AcceptInvitationPage() {
                 </div>
               )}
 
-              {hasLoginToken && authenticatedInvitationAcceptanceEnabled ? (
+              {!invitationCapabilitiesLoaded ? (
+                <div className="flex justify-center py-8">
+                  <Loader2 className="size-6 animate-spin" />
+                </div>
+              ) : hasLoginToken && authenticatedInvitationAcceptanceEnabled ? (
                 <Button
                   className="w-full"
                   disabled={status === 'submitting'}
@@ -331,7 +341,7 @@ export default function AcceptInvitationPage() {
                     {t('workspace.logoutAndReturn')}
                   </Button>
                 </div>
-              ) : passwordRegistrationEnabled ? (
+              ) : invitationRegistrationEnabled ? (
                 <>
                   <div className="space-y-2">
                     <label