feat(sdk-coin-polyx): add v8 metadata and base V8 builders

Add Polymesh v8 chain resources and V8-prefixed transaction builder
classes to support the Polymesh spec-version 8 migration.

What changed:
- src/resources/mainnetV8.ts, testnetV8.ts: new material files with
  specVersion 8000000 and txVersion 8 (metadata bytes identical to v7
  placeholder, to be replaced once v8 chain launches).
- src/resources/index.ts: re-export mainnetV8 and testnetV8.
- src/lib/utils.ts: add getV8Material() helper, mirrors getMaterial().
- src/lib/v8TransferBuilder.ts: V8TransferBuilder — v8 material.
- src/lib/v8HexTransferBuilder.ts: V8HexTransferBuilder — v8 material.
- src/lib/v8RegisterDidWithCDDBuilder.ts: V8RegisterDidWithCDDBuilder.
- src/lib/v8TokenTransferBuilder.ts: V8TokenTransferBuilder.
- src/lib/v8HexTokenTransferBuilder.ts: V8HexTokenTransferBuilder.
- src/lib/v8PreApproveAssetBuilder.ts: V8PreApproveAssetBuilder.
- src/lib/transactionBuilderFactory.ts: six getV8*Builder() factory
  methods exposing the V8 builders through the standard factory.
- src/lib/index.ts: export all six V8 builder classes.
- src/lib/preApproveAssetBuilder.ts: remove stray console.log.
- test/unit/transactionBuilder/v8*.ts: 25 unit tests verifying each
  V8 builder uses v8 material (specVersion/txVersion), that factory
  methods return the correct subclass, and that signed transactions
  encode the correct chain metadata in toJson() output.

Why: Polymesh is upgrading its chain runtime from spec version 7 to
version 8 (CECHO-1471 / Polymesh v8 Migration — BASE-2). Downstream
services (HSM, wallet-platform, indexer) need dedicated V8 builder
classes and factory methods so they can construct and sign v8
transactions independently of the existing v7 builders without
breaking any in-flight v7 traffic.

Ticket: CECHO-1471
Session-Id: d224e5fe-f47a-4f84-9e84-c680f3085842
Task-Id: b5392230-7ea0-47bb-be33-bee96e8ec7bb

Author: nvrakesh06

modules/sdk-coin-polyx/src/lib/index.ts

@@ -24,6 +24,12 @@ export { NominateBuilder } from './nominateBuilder';
 export { BatchUnstakingBuilder } from './batchUnstakingBuilder';
 export { UnbondBuilder } from './unbondBuilder';
 export { WithdrawUnbondedBuilder } from './withdrawUnbondedBuilder';
+export { V8TransferBuilder } from './v8TransferBuilder';
+export { V8HexTransferBuilder } from './v8HexTransferBuilder';
+export { V8RegisterDidWithCDDBuilder } from './v8RegisterDidWithCDDBuilder';
+export { V8TokenTransferBuilder } from './v8TokenTransferBuilder';
+export { V8HexTokenTransferBuilder } from './v8HexTokenTransferBuilder';
+export { V8PreApproveAssetBuilder } from './v8PreApproveAssetBuilder';
 import polyxUtils from './utils';
 export { Utils, default as utils } from './utils';
 export * from './iface';

modules/sdk-coin-polyx/src/lib/preApproveAssetBuilder.ts

@@ -74,7 +74,6 @@ export class PreApproveAssetBuilder extends PolyxBaseBuilder<TxMethod, Transacti
    * @returns {UnsignedTransaction} an unsigned transaction for asset pre-approval
    */
   private preApproveAsset(args: PreApproveAssetArgs, info: Interface.CreateBaseTxInfo): UnsignedTransaction {
-    console.log(`PreApproveAssetBuilder: preApproveAsset called with args: ${JSON.stringify(args)}`);
     return defineMethod(
       {
         method: {

modules/sdk-coin-polyx/src/lib/transactionBuilderFactory.ts

@@ -19,6 +19,12 @@ import { TokenTransferBuilder } from './tokenTransferBuilder';
 import { HexTokenTransferBuilder } from './hexTokenTransferBuilder';
 import { RejectInstructionBuilder } from './rejectInstructionBuilder';
 import { NominateBuilder } from './nominateBuilder';
+import { V8TransferBuilder } from './v8TransferBuilder';
+import { V8HexTransferBuilder } from './v8HexTransferBuilder';
+import { V8RegisterDidWithCDDBuilder } from './v8RegisterDidWithCDDBuilder';
+import { V8TokenTransferBuilder } from './v8TokenTransferBuilder';
+import { V8HexTokenTransferBuilder } from './v8HexTokenTransferBuilder';
+import { V8PreApproveAssetBuilder } from './v8PreApproveAssetBuilder';
 
 export type SupportedTransaction = BaseTransaction | PolyxTransaction;
 
@@ -82,6 +88,30 @@ export class TransactionBuilderFactory extends BaseTransactionBuilderFactory {
     return new NominateBuilder(this._coinConfig).material(this._material);
   }
 
+  getV8TransferBuilder(): V8TransferBuilder {
+    return new V8TransferBuilder(this._coinConfig);
+  }
+
+  getV8HexTransferBuilder(): V8HexTransferBuilder {
+    return new V8HexTransferBuilder(this._coinConfig);
+  }
+
+  getV8RegisterDidWithCDDBuilder(): V8RegisterDidWithCDDBuilder {
+    return new V8RegisterDidWithCDDBuilder(this._coinConfig);
+  }
+
+  getV8TokenTransferBuilder(): V8TokenTransferBuilder {
+    return new V8TokenTransferBuilder(this._coinConfig);
+  }
+
+  getV8HexTokenTransferBuilder(): V8HexTokenTransferBuilder {
+    return new V8HexTokenTransferBuilder(this._coinConfig);
+  }
+
+  getV8PreApproveAssetBuilder(): V8PreApproveAssetBuilder {
+    return new V8PreApproveAssetBuilder(this._coinConfig);
+  }
+
   getWalletInitializationBuilder(): void {
     throw new NotImplementedError(`walletInitialization for ${this._coinConfig.name} not implemented`);
   }

modules/sdk-coin-polyx/src/lib/utils.ts

@@ -1,7 +1,7 @@
 import { Utils as SubstrateUtils, Interface } from '@bitgo/abstract-substrate';
 import { NetworkType } from '@bitgo/statics';
 import { TypeRegistry } from '@substrate/txwrapper-core/lib/types';
-import { mainnetMaterial, testnetMaterial } from '../resources';
+import { mainnetMaterial, testnetMaterial, mainnetV8Material, testnetV8Material } from '../resources';
 import { BatchCallObject } from './iface';
 import { MEMO_HEX_REGEX, MEMO_MAX_BYTES, POLYX_DID_REGEX } from './constants';
 
@@ -77,6 +77,12 @@ export class Utils extends SubstrateUtils {
     return (networkType === NetworkType.MAINNET ? mainnetMaterial : testnetMaterial) as unknown as Interface.Material;
   }
 
+  getV8Material(networkType: NetworkType): Interface.Material {
+    return (networkType === NetworkType.MAINNET
+      ? mainnetV8Material
+      : testnetV8Material) as unknown as Interface.Material;
+  }
+
   decodeMethodName(call: BatchCallObject, registry: TypeRegistry): string {
     // Handle both callIndex and method formats
     const callWithIndex = call as BatchCallObject & { callIndex?: string };

modules/sdk-coin-polyx/src/lib/v8HexTokenTransferBuilder.ts

@@ -0,0 +1,15 @@
+import { BaseCoin as CoinConfig } from '@bitgo/statics';
+import { HexTokenTransferBuilder } from './hexTokenTransferBuilder';
+import utils from './utils';
+
+/**
+ * Builds a Polymesh settlement.addAndAffirmWithMediators transaction using
+ * the hex (NEW) memo encoding against Polymesh v8 chain metadata. Identical
+ * behaviour to HexTokenTransferBuilder; only the material differs.
+ */
+export class V8HexTokenTransferBuilder extends HexTokenTransferBuilder {
+  constructor(_coinConfig: Readonly<CoinConfig>) {
+    super(_coinConfig);
+    this.material(utils.getV8Material(_coinConfig.network.type));
+  }
+}

modules/sdk-coin-polyx/src/lib/v8HexTransferBuilder.ts

@@ -0,0 +1,15 @@
+import { BaseCoin as CoinConfig } from '@bitgo/statics';
+import { HexTransferBuilder } from './hexTransferBuilder';
+import utils from './utils';
+
+/**
+ * Builds a POLYX balances.transferWithMemo transaction using the hex
+ * (NEW) memo encoding against Polymesh v8 chain metadata. Identical
+ * behaviour to HexTransferBuilder; only the material differs.
+ */
+export class V8HexTransferBuilder extends HexTransferBuilder {
+  constructor(_coinConfig: Readonly<CoinConfig>) {
+    super(_coinConfig);
+    this.material(utils.getV8Material(_coinConfig.network.type));
+  }
+}

modules/sdk-coin-polyx/src/lib/v8PreApproveAssetBuilder.ts

@@ -0,0 +1,15 @@
+import { BaseCoin as CoinConfig } from '@bitgo/statics';
+import { PreApproveAssetBuilder } from './preApproveAssetBuilder';
+import utils from './utils';
+
+/**
+ * Builds a Polymesh asset.preApproveAsset transaction against Polymesh v8
+ * chain metadata. Identical behaviour to PreApproveAssetBuilder; only the
+ * material differs.
+ */
+export class V8PreApproveAssetBuilder extends PreApproveAssetBuilder {
+  constructor(_coinConfig: Readonly<CoinConfig>) {
+    super(_coinConfig);
+    this.material(utils.getV8Material(_coinConfig.network.type));
+  }
+}

modules/sdk-coin-polyx/src/lib/v8RegisterDidWithCDDBuilder.ts

@@ -0,0 +1,15 @@
+import { BaseCoin as CoinConfig } from '@bitgo/statics';
+import { RegisterDidWithCDDBuilder } from './registerDidWithCDDBuilder';
+import utils from './utils';
+
+/**
+ * Builds a Polymesh identity.cddRegisterDidWithCdd transaction against
+ * Polymesh v8 chain metadata. Identical behaviour to
+ * RegisterDidWithCDDBuilder; only the material differs.
+ */
+export class V8RegisterDidWithCDDBuilder extends RegisterDidWithCDDBuilder {
+  constructor(_coinConfig: Readonly<CoinConfig>) {
+    super(_coinConfig);
+    this.material(utils.getV8Material(_coinConfig.network.type));
+  }
+}

modules/sdk-coin-polyx/src/lib/v8TokenTransferBuilder.ts

@@ -0,0 +1,15 @@
+import { BaseCoin as CoinConfig } from '@bitgo/statics';
+import { TokenTransferBuilder } from './tokenTransferBuilder';
+import utils from './utils';
+
+/**
+ * Builds a Polymesh settlement.addAndAffirmWithMediators transaction against
+ * Polymesh v8 chain metadata. Identical behaviour to TokenTransferBuilder;
+ * only the material differs.
+ */
+export class V8TokenTransferBuilder extends TokenTransferBuilder {
+  constructor(_coinConfig: Readonly<CoinConfig>) {
+    super(_coinConfig);
+    this.material(utils.getV8Material(_coinConfig.network.type));
+  }
+}

modules/sdk-coin-polyx/src/lib/v8TransferBuilder.ts

@@ -0,0 +1,15 @@
+import { BaseCoin as CoinConfig } from '@bitgo/statics';
+import { TransferBuilder } from './transferBuilder';
+import utils from './utils';
+
+/**
+ * Builds a POLYX balances.transferWithMemo transaction against Polymesh v8
+ * chain metadata. Identical behaviour to TransferBuilder; only the material
+ * (specVersion / txVersion) differs.
+ */
+export class V8TransferBuilder extends TransferBuilder {
+  constructor(_coinConfig: Readonly<CoinConfig>) {
+    super(_coinConfig);
+    this.material(utils.getV8Material(_coinConfig.network.type));
+  }
+}