chore(docs): update payment manager setup

Author: Ansonhkg

docs/sdk/getting-started/payment-manager-setup.mdx

@@ -158,7 +158,7 @@ const response = await litClient.decrypt({
   unifiedAccessControlConditions: accs,
   authContext,
   chain: 'ethereum',
-  userMaxPrice: BigInt('200000000000000000'), // optional guardrail
+  userMaxPrice: 1000000000000000000n, // required for sponsored sessions, typically the same value as the restriction the sponsor set; optional guardrail when self-funded
 });
 ```
 

packages/lit-client/src/lib/LitClient/createLitClient.ts

@@ -919,6 +919,7 @@ export const _createNagaLitClient = async (
       pkpPublicKey: string | Hex;
       authContext: AuthContextSchema2;
       chainConfig: Chain;
+      userMaxPrice?: bigint
     }) => {
       const _pkpPublicKey = HexPrefixedSchema.parse(params.pkpPublicKey);
 
@@ -934,6 +935,7 @@ export const _createNagaLitClient = async (
             toSign: data,
             authContext: params.authContext,
             bypassAutoHashing: options?.bypassAutoHashing,
+            userMaxPrice: params.userMaxPrice,
           });
 
           return res.signature;