feat(utxo-core): support custom input sequence in transaction creation

Allow specifying sequence number per transaction input rather than
globally, while maintaining backward compatibility.

Issue: BTC-1966
Co-authored-by: llm-git <[email protected]>

Author: OttoAllmendinger

modules/utxo-core/src/descriptor/psbt/createPsbt.ts

@@ -48,15 +48,19 @@ export type PsbtParams = {
   sequence?: number;
 };
 
+export type DerivedDescriptorTransactionInput = DerivedDescriptorWalletOutput & {
+  sequence?: number;
+};
+
 export function createPsbt(
   params: PsbtParams,
-  inputs: DerivedDescriptorWalletOutput[],
+  inputs: DerivedDescriptorTransactionInput[],
   outputs: WithOptDescriptor<Output>[]
 ): utxolib.bitgo.UtxoPsbt {
   const psbt = utxolib.bitgo.UtxoPsbt.createPsbt({ network: params.network });
   psbt.setVersion(params.version ?? 2);
   psbt.setLocktime(params.locktime ?? 0);
-  psbt.addInputs(inputs.map((i) => ({ ...i, sequence: params.sequence ?? MAX_BIP125_RBF_SEQUENCE })));
+  psbt.addInputs(inputs.map((i) => ({ ...i, sequence: i.sequence ?? params.sequence ?? MAX_BIP125_RBF_SEQUENCE })));
   psbt.addOutputs(outputs);
   updateInputsWithDescriptors(
     psbt,

modules/utxo-core/src/testutil/descriptor/mock.utils.ts

@@ -1,8 +1,12 @@
 import { Descriptor } from '@bitgo/wasm-miniscript';
 import * as utxolib from '@bitgo/utxo-lib';
 
-import { PsbtParams, createPsbt, createScriptPubKeyFromDescriptor } from '../../descriptor';
-import { DerivedDescriptorWalletOutput } from '../../descriptor/Output';
+import {
+  PsbtParams,
+  createPsbt,
+  createScriptPubKeyFromDescriptor,
+  DerivedDescriptorTransactionInput,
+} from '../../descriptor';
 
 import { DescriptorTemplate, getDefaultXPubs, getDescriptor } from './descriptors';
 
@@ -12,6 +16,7 @@ type BaseMockDescriptorOutputParams = {
   id?: MockOutputIdParams;
   index?: number;
   value?: bigint;
+  sequence?: number;
 };
 
 function mockOutputId(id?: MockOutputIdParams): {
@@ -26,7 +31,7 @@ function mockOutputId(id?: MockOutputIdParams): {
 export function mockDerivedDescriptorWalletOutput(
   descriptor: Descriptor,
   outputParams: BaseMockDescriptorOutputParams = {}
-): DerivedDescriptorWalletOutput {
+): DerivedDescriptorTransactionInput {
   const { value = BigInt(1e6) } = outputParams;
   const { hash, vout } = mockOutputId(outputParams.id);
   return {
@@ -37,6 +42,7 @@ export function mockDerivedDescriptorWalletOutput(
       value,
     },
     descriptor,
+    sequence: outputParams.sequence,
   };
 }