feat(sdk-api): add isTestTransaction support

for withdrawals

Add isTestTransaction parameter support for wallet transactions:
- Add isTestTransaction to PrebuildTransactionOptions interface
 (available for both TSS and multisig wallets)
- Pass isTestTransaction through prebuildTransactionTxRequests
for TSS transfer transactions
- Include isTestTransaction in PopulatedIntent and baseIntent
objects for TSS wallet flow
- SendManyOptions inherits isTestTransaction via
PrebuildAndSignTransactionOptions

Add comprehensive test coverage:
- Test isTestTransaction is passed through prebuildTransaction for TSS wallets
- Test isTestTransaction flows through sendMany to prebuildAndSignTransaction
- Add proper TypeScript assertions with existence checks

This ensures the isTestTransaction flag is correctly sent to the
/api/v2/wallet/:walletId/txrequests endpoint for TSS wallets (e.g., NEAR)
and is available for multisig wallets when building transfer transactions
via prebuildTransaction() or sendMany().

TICKET: CS-6399

Author: sandra-wang-bitgo

modules/bitgo/test/v2/unit/wallet.ts

@@ -2362,6 +2362,50 @@ describe('V2 Wallet:', function () {
         });
       });
 
+      it('should build a transfer transaction with isTestTransaction flag', async function () {
+        const recipients = [
+          {
+            address: '6DadkZcx9JZgeQUDbHh12cmqCpaqehmVxv6sGy49jrah',
+            amount: '1000',
+          },
+        ];
+
+        const prebuildTxWithIntent = sandbox.stub(TssUtils.prototype, 'prebuildTxWithIntent');
+        prebuildTxWithIntent.resolves(txRequest);
+
+        const txPrebuild = await tssSolWallet.prebuildTransaction({
+          reqId,
+          recipients,
+          type: 'transfer',
+          isTestTransaction: true,
+        });
+
+        // Verify isTestTransaction is passed to prebuildTxWithIntent
+        sinon.assert.calledOnce(prebuildTxWithIntent);
+        const callArgs = prebuildTxWithIntent.getCall(0).args[0];
+        callArgs.should.have.property('isTestTransaction', true);
+        callArgs.should.have.property('intentType', 'payment');
+        callArgs.should.have.property('recipients');
+        should.exist(callArgs.recipients);
+        callArgs.recipients!.should.deepEqual(recipients);
+
+        txPrebuild.should.deepEqual({
+          walletId: tssSolWallet.id(),
+          wallet: tssSolWallet,
+          txRequestId: 'id',
+          txHex: 'ababcdcd',
+          buildParams: {
+            recipients,
+            type: 'transfer',
+            isTestTransaction: true,
+          },
+          feeInfo: {
+            fee: 5000,
+            feeString: '5000',
+          },
+        });
+      });
+
       it('should build an enable token transaction', async function () {
         const recipients = [];
         const tokenName = 'tcoin:tokenName';
@@ -3909,6 +3953,35 @@ describe('V2 Wallet:', function () {
         setRequestTracerSpy.restore();
       });
 
+      it('should pass isTestTransaction through sendMany to prebuildAndSignTransaction', async function () {
+        const signedTransaction = {
+          txRequestId: 'txRequestId',
+        };
+
+        const sendManyInputWithTestFlag = {
+          ...sendManyInput,
+          type: 'transfer',
+          isTestTransaction: true,
+        };
+
+        const prebuildAndSignTransaction = sandbox.stub(tssSolWallet, 'prebuildAndSignTransaction');
+        prebuildAndSignTransaction.resolves(signedTransaction);
+
+        const sendTxRequest = sandbox.stub(TssUtils.prototype, 'sendTxRequest');
+        sendTxRequest.resolves('sendTxResponse');
+
+        const sendMany = await tssSolWallet.sendMany(sendManyInputWithTestFlag);
+
+        // Verify prebuildAndSignTransaction was called with isTestTransaction
+        sinon.assert.calledOnce(prebuildAndSignTransaction);
+        const callArgs = prebuildAndSignTransaction.getCall(0).args[0];
+        should.exist(callArgs);
+        callArgs!.should.have.property('isTestTransaction', true);
+        callArgs!.should.have.property('type', 'transfer');
+
+        sendMany.should.deepEqual('sendTxResponse');
+      });
+
       it('should return transfer from sendMany for apiVersion=full', async function () {
         const wallet = new Wallet(bitgo, tsol, {
           ...walletData,

modules/sdk-core/src/bitgo/utils/mpcUtils.ts

@@ -188,6 +188,7 @@ export abstract class MpcUtils {
       nonce: params.nonce,
       recipients: intentRecipients,
       tokenName: params.tokenName,
+      isTestTransaction: params.isTestTransaction,
     };
 
     if (baseCoin.getFamily() === 'eth' || baseCoin.getFamily() === 'polygon' || baseCoin.getFamily() === 'bsc') {

modules/sdk-core/src/bitgo/utils/tss/baseTypes.ts

@@ -269,6 +269,7 @@ export interface PrebuildTransactionWithIntentOptions extends IntentOptionsBase
     abi?: any;
   };
   txRequestId?: string;
+  isTestTransaction?: boolean;
 }
 export interface IntentRecipient {
   address: {
@@ -338,6 +339,7 @@ export interface PopulatedIntent extends PopulatedIntentBase {
    */
   aptosCustomTransactionParams?: aptosCustomTransactionParams;
   txRequestId?: string;
+  isTestTransaction?: boolean;
 }
 
 export type TxRequestState =

modules/sdk-core/src/bitgo/wallet/BuildParams.ts

@@ -116,6 +116,7 @@ export const BuildParams = t.exact(
       solVersionedTransactionData: t.unknown,
       // Aptos custom transaction parameters for smart contract calls
       aptosCustomTransactionParams: t.unknown,
+      isTestTransaction: t.unknown,
     }),
   ])
 );

modules/sdk-core/src/bitgo/wallet/iWallet.ts

@@ -217,6 +217,7 @@ export interface PrebuildTransactionOptions {
     abi?: any;
   };
   txRequestId?: string;
+  isTestTransaction?: boolean;
 }
 
 export interface PrebuildAndSignTransactionOptions extends PrebuildTransactionOptions, WalletSignTransactionOptions {

modules/sdk-core/src/bitgo/wallet/wallet.ts

@@ -3434,6 +3434,7 @@ export class Wallet implements IWallet {
             custodianTransactionId: params.custodianTransactionId,
             unspents: params.unspents,
             senderAddress: params.senderAddress,
+            isTestTransaction: params.isTestTransaction,
           },
           apiVersion,
           params.preview