cleanup host on idp login

apps/login/src/app/(login)/loginname/page.tsx

@@ -30,10 +30,6 @@ export default async function Page(props: {
     }
   }
 
-  const host = process.env.VERCEL_URL
-    ? `https://${process.env.VERCEL_URL}`
-    : "http://localhost:3000";
-
   const loginSettings = await getLoginSettings(
     organization ?? defaultOrganization,
   );
@@ -63,7 +59,6 @@ export default async function Page(props: {
         >
           {identityProviders && (
             <SignInWithIdp
-              host={host}
               identityProviders={identityProviders}
               authRequestId={authRequestId}
               organization={organization ?? defaultOrganization} // use the organization from the searchParams here otherwise fallback to the default organization

apps/login/src/components/sign-in-with-idp.tsx

@@ -6,6 +6,7 @@ import {
   IdentityProvider,
   IdentityProviderType,
 } from "@zitadel/proto/zitadel/settings/v2/login_settings_pb";
+import { headers } from "next/headers";
 import { useRouter } from "next/navigation";
 import { ReactNode, useState } from "react";
 import { Alert } from "./alert";
@@ -18,7 +19,6 @@ import { SignInWithGoogle } from "./idps/sign-in-with-google";
 
 export interface SignInWithIDPProps {
   children?: ReactNode;
-  host: string;
   identityProviders: IdentityProvider[];
   authRequestId?: string;
   organization?: string;
@@ -26,7 +26,6 @@ export interface SignInWithIDPProps {
 }
 
 export function SignInWithIdp({
-  host,
   identityProviders,
   authRequestId,
   organization,
@@ -53,6 +52,8 @@ export function SignInWithIdp({
       params.set("organization", organization);
     }
 
+    const host = (await headers()).get("host");
+
     const response = await startIDPFlow({
       idpId,
       successUrl: