feat(pox-4): Add amountUnlocked to Wallet for staking

Introduces `amountUnlocked` to the Wallet model in PoX-4 tests to
clearly differentiate between locked and available balances. This
addition complements the existing balance field, enhancing
understanding of staking dynamics without renaming or removing
existing structures. Adjustments made in related commands and tests
ensure accuracy and consistency.

contrib/core-contract-tests/tests/pox-4/pox-4.stateful-prop.test.ts

@@ -46,6 +46,7 @@ describe("PoX-4 invariant tests", () => {
       const prvKey = wallet[1];
       const pubKey = getPublicKeyFromPrivate(prvKey);
       const devnet = new StacksDevnet();
+      const initialUstxBalance = 100_000_000_000_000;
       const signerPrvKey = createStacksPrivateKey(prvKey);
       const signerPubKey = getPublicKeyFromPrivate(signerPrvKey.data);
       const btcAddress = publicKeyToBtcAddress(pubKey);
@@ -61,11 +62,12 @@ describe("PoX-4 invariant tests", () => {
         signerPrvKey,
         signerPubKey,
         stackingClient: new StackingClient(stxAddress, devnet),
-        ustxBalance: 100_000_000_000_000,
+        ustxBalance: initialUstxBalance,
         isStacking: false,
         hasDelegated: false,
         delegatedTo: "",
         amountLocked: 0,
+        amountUnlocked: initialUstxBalance,
         unlockHeight: 0,
       };
     });

contrib/core-contract-tests/tests/pox-4/pox_CommandModel.ts

@@ -27,6 +27,7 @@ export type Wallet = {
   hasDelegated: boolean;
   delegatedTo: StxAddress;
   amountLocked: number;
+  amountUnlocked: number;
   unlockHeight: number;
 };
 

contrib/core-contract-tests/tests/pox-4/pox_GetStxAccountCommand.ts

@@ -29,7 +29,7 @@ export class GetStxAccountCommand implements PoxCommand {
     expect(real.network.runSnippet(`(stx-account '${actual.stxAddress})`))
       .toBeTuple({
         "locked": Cl.uint(actual.amountLocked),
-        "unlocked": Cl.uint(actual.ustxBalance),
+        "unlocked": Cl.uint(actual.amountUnlocked),
         "unlock-height": Cl.uint(actual.unlockHeight),
       });
 
@@ -41,7 +41,7 @@ export class GetStxAccountCommand implements PoxCommand {
       } ${"lock-amount".padStart(12, " ")} ${
         actual.amountLocked.toString().padStart(13, " ")
       } ${"unlocked-amount".padStart(12, " ")} ${
-        actual.ustxBalance.toString().padStart(15, " ")
+        actual.amountUnlocked.toString().padStart(15, " ")
       } ${"unlocked-height".padStart(12, " ")} ${
         actual.unlockHeight.toString().padStart(7, " ")
       }`,

contrib/core-contract-tests/tests/pox-4/pox_StackStxCommand.ts

@@ -151,7 +151,7 @@ export class StackStxCommand implements PoxCommand {
     // Update locked, unlocked, and unlock-height fields in the model.
     wallet.amountLocked = amountUstx;
     wallet.unlockHeight = Number(unlockBurnHeight.value);
-    wallet.ustxBalance -= amountUstx;
+    wallet.amountUnlocked -= amountUstx;
 
     // Log to console for debugging purposes. This is not necessary for the
     // test to pass but it is useful for debugging and eyeballing the test.