fix(react): switch chains for SIWE (#4047)

## Problem solved

Short description of the bug fixed or feature added

<!-- start pr-codex -->

---

## PR-Codex overview
This PR focuses on updating authentication logic to switch to the proper chain before signing payloads.

### Detailed summary
- Updated `getLoginPayload` to include `chainId` parameter
- Added logic to switch to the correct chain before signing payloads
- Updated initialization of `thirdwebAuth` to handle chain switching
- Imported `getCachedChain` function in `useSiweAuth.ts`

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<!-- end pr-codex -->

.changeset/forty-tools-hear.md

@@ -0,0 +1,5 @@
+---
+"thirdweb": patch
+---
+
+Switch to the proper chain prior to signing SIWE payloads

apps/playground-web/src/app/connect/auth/server/actions/auth.ts

@@ -9,6 +9,7 @@ const privateKey = process.env.THIRDWEB_ADMIN_PRIVATE_KEY;
 
 const thirdwebAuth = createAuth({
   domain: process.env.NEXT_PUBLIC_THIRDWEB_AUTH_DOMAIN || "",
+  client: THIRDWEB_CLIENT,
   adminAccount: privateKey
     ? privateKeyToAccount({ client: THIRDWEB_CLIENT, privateKey })
     : await generateAccount({ client: THIRDWEB_CLIENT }),

apps/playground-web/src/components/auth/auth-button.tsx

@@ -16,7 +16,8 @@ export function AuthButton() {
       auth={{
         isLoggedIn: (address) => isLoggedIn(address),
         doLogin: (params) => login(params),
-        getLoginPayload: ({ address }) => generatePayload({ address }),
+        getLoginPayload: ({ address }) =>
+          generatePayload({ address, chainId: 84532 }),
         doLogout: () => logout(),
       }}
     />

packages/thirdweb/src/react/core/hooks/auth/useSiweAuth.ts

@@ -1,6 +1,7 @@
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import type { LoginPayload } from "../../../../auth/core/types.js";
 import type { VerifyLoginPayloadParams } from "../../../../auth/core/verify-login-payload.js";
+import { getCachedChain } from "../../../../chains/utils.js";
 import type { Account, Wallet } from "../../../../wallets/interfaces/wallet.js";
 
 /**
@@ -95,6 +96,12 @@ export function useSiweAuth(
         import("../../../../auth/core/sign-login-payload.js"),
       ]);
 
+      if (payload.chain_id) {
+        await activeWallet.switchChain(
+          getCachedChain(Number(payload.chain_id)),
+        );
+      }
+
       const signedPayload = await signLoginPayload({
         payload,
         account: activeAccount,