refactor: move brother_node development artifact to dev/test-nodes subdirectory

Development Artifact Cleanup:
✅ BROTHER_NODE REORGANIZATION: Moved development test node to appropriate location
- dev/test-nodes/brother_node/: Moved from root directory for better organization
- Contains development configuration, test logs, and test chain data
- No impact on production systems - purely development/testing artifact

✅ DEVELOPMENT ARTIFACTS IDENTIFIED:
- Chain ID: aitbc-brother-chain (test/development chain)
- Ports: 8010 (P2P) and 8011 (RPC) - different from production
- Environment: .env file with test configuration
- Logs: rpc.log and node.log from development testing session (March 15, 2026)

✅ ROOT DIRECTORY CLEANUP: Removed development clutter from production directory
- brother_node/ moved to dev/test-nodes/brother_node/
- Root directory now contains only production-ready components
- Development artifacts properly organized in dev/ subdirectory

DIRECTORY STRUCTURE IMPROVEMENT:
📁 dev/test-nodes/: Development and testing node configurations
🏗️ Root Directory: Clean production structure with only essential components
🧪 Development Isolation: Test environments separated from production

BENEFITS:
✅ Clean Production Directory: No development artifacts in root
✅ Better Organization: Development nodes grouped in dev/ subdirectory
✅ Clear Separation: Production vs development environments clearly distinguished
✅ Maintainability: Easier to identify and manage development components

RESULT: Successfully moved brother_node development artifact to dev/test-nodes/ subdirectory, cleaning up the root directory while preserving development testing environment for future use.

dev/env/node_modules/hardhat/templates/hardhat-2/04-mocha-viem-ts/test/Lock.ts

@@ -0,0 +1,134 @@
+import {
+  time,
+  loadFixture,
+} from "@nomicfoundation/hardhat-toolbox-viem/network-helpers";
+import { expect } from "chai";
+import hre from "hardhat";
+import { getAddress, parseGwei } from "viem";
+
+describe("Lock", function () {
+  // We define a fixture to reuse the same setup in every test.
+  // We use loadFixture to run this setup once, snapshot that state,
+  // and reset Hardhat Network to that snapshot in every test.
+  async function deployOneYearLockFixture() {
+    const ONE_YEAR_IN_SECS = 365 * 24 * 60 * 60;
+
+    const lockedAmount = parseGwei("1");
+    const unlockTime = BigInt((await time.latest()) + ONE_YEAR_IN_SECS);
+
+    // Contracts are deployed using the first signer/account by default
+    const [owner, otherAccount] = await hre.viem.getWalletClients();
+
+    const lock = await hre.viem.deployContract("Lock", [unlockTime], {
+      value: lockedAmount,
+    });
+
+    const publicClient = await hre.viem.getPublicClient();
+
+    return {
+      lock,
+      unlockTime,
+      lockedAmount,
+      owner,
+      otherAccount,
+      publicClient,
+    };
+  }
+
+  describe("Deployment", function () {
+    it("Should set the right unlockTime", async function () {
+      const { lock, unlockTime } = await loadFixture(deployOneYearLockFixture);
+
+      expect(await lock.read.unlockTime()).to.equal(unlockTime);
+    });
+
+    it("Should set the right owner", async function () {
+      const { lock, owner } = await loadFixture(deployOneYearLockFixture);
+
+      expect(await lock.read.owner()).to.equal(
+        getAddress(owner.account.address),
+      );
+    });
+
+    it("Should receive and store the funds to lock", async function () {
+      const { lock, lockedAmount, publicClient } = await loadFixture(
+        deployOneYearLockFixture,
+      );
+
+      expect(
+        await publicClient.getBalance({
+          address: lock.address,
+        }),
+      ).to.equal(lockedAmount);
+    });
+
+    it("Should fail if the unlockTime is not in the future", async function () {
+      // We don't use the fixture here because we want a different deployment
+      const latestTime = BigInt(await time.latest());
+      await expect(
+        hre.viem.deployContract("Lock", [latestTime], {
+          value: 1n,
+        }),
+      ).to.be.rejectedWith("Unlock time should be in the future");
+    });
+  });
+
+  describe("Withdrawals", function () {
+    describe("Validations", function () {
+      it("Should revert with the right error if called too soon", async function () {
+        const { lock } = await loadFixture(deployOneYearLockFixture);
+
+        await expect(lock.write.withdraw()).to.be.rejectedWith(
+          "You can't withdraw yet",
+        );
+      });
+
+      it("Should revert with the right error if called from another account", async function () {
+        const { lock, unlockTime, otherAccount } = await loadFixture(
+          deployOneYearLockFixture,
+        );
+
+        // We can increase the time in Hardhat Network
+        await time.increaseTo(unlockTime);
+
+        // We retrieve the contract with a different account to send a transaction
+        const lockAsOtherAccount = await hre.viem.getContractAt(
+          "Lock",
+          lock.address,
+          { client: { wallet: otherAccount } },
+        );
+        await expect(lockAsOtherAccount.write.withdraw()).to.be.rejectedWith(
+          "You aren't the owner",
+        );
+      });
+
+      it("Shouldn't fail if the unlockTime has arrived and the owner calls it", async function () {
+        const { lock, unlockTime } = await loadFixture(
+          deployOneYearLockFixture,
+        );
+
+        // Transactions are sent using the first signer by default
+        await time.increaseTo(unlockTime);
+
+        await expect(lock.write.withdraw()).to.be.fulfilled;
+      });
+    });
+
+    describe("Events", function () {
+      it("Should emit an event on withdrawals", async function () {
+        const { lock, unlockTime, lockedAmount, publicClient } =
+          await loadFixture(deployOneYearLockFixture);
+
+        await time.increaseTo(unlockTime);
+
+        const hash = await lock.write.withdraw();
+        await publicClient.waitForTransactionReceipt({ hash });
+
+        // get the withdrawal events in the latest block
+        const withdrawalEvents = await lock.getEvents.Withdrawal();
+        expect(withdrawalEvents).to.have.lengthOf(1);
+        expect(withdrawalEvents[0].args.amount).to.equal(lockedAmount);
+      });
+    });
+  });
+});