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-3/01-node-test-runner-viem/README.md

@@ -0,0 +1,57 @@
+# Sample Hardhat 3 Beta Project (`node:test` and `viem`)
+
+This project showcases a Hardhat 3 Beta project using the native Node.js test runner (`node:test`) and the `viem` library for Ethereum interactions.
+
+To learn more about the Hardhat 3 Beta, please visit the [Getting Started guide](https://hardhat.org/docs/getting-started#getting-started-with-hardhat-3). To share your feedback, join our [Hardhat 3 Beta](https://hardhat.org/hardhat3-beta-telegram-group) Telegram group or [open an issue](https://github.com/NomicFoundation/hardhat/issues/new) in our GitHub issue tracker.
+
+## Project Overview
+
+This example project includes:
+
+- A simple Hardhat configuration file.
+- Foundry-compatible Solidity unit tests.
+- TypeScript integration tests using [`node:test`](nodejs.org/api/test.html), the new Node.js native test runner, and [`viem`](https://viem.sh/).
+- Examples demonstrating how to connect to different types of networks, including locally simulating OP mainnet.
+
+## Usage
+
+### Running Tests
+
+To run all the tests in the project, execute the following command:
+
+```shell
+npx hardhat test
+```
+
+You can also selectively run the Solidity or `node:test` tests:
+
+```shell
+npx hardhat test solidity
+npx hardhat test nodejs
+```
+
+### Make a deployment to Sepolia
+
+This project includes an example Ignition module to deploy the contract. You can deploy this module to a locally simulated chain or to Sepolia.
+
+To run the deployment to a local chain:
+
+```shell
+npx hardhat ignition deploy ignition/modules/Counter.ts
+```
+
+To run the deployment to Sepolia, you need an account with funds to send the transaction. The provided Hardhat configuration includes a Configuration Variable called `SEPOLIA_PRIVATE_KEY`, which you can use to set the private key of the account you want to use.
+
+You can set the `SEPOLIA_PRIVATE_KEY` variable using the `hardhat-keystore` plugin or by setting it as an environment variable.
+
+To set the `SEPOLIA_PRIVATE_KEY` config variable using `hardhat-keystore`:
+
+```shell
+npx hardhat keystore set SEPOLIA_PRIVATE_KEY
+```
+
+After setting the variable, you can run the deployment with the Sepolia network:
+
+```shell
+npx hardhat ignition deploy --network sepolia ignition/modules/Counter.ts
+```

dev/env/node_modules/hardhat/templates/hardhat-3/01-node-test-runner-viem/contracts/Counter.sol

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.28;
+
+contract Counter {
+  uint public x;
+
+  event Increment(uint by);
+
+  function inc() public {
+    x++;
+    emit Increment(1);
+  }
+
+  function incBy(uint by) public {
+    require(by > 0, "incBy: increment should be positive");
+    x += by;
+    emit Increment(by);
+  }
+}

dev/env/node_modules/hardhat/templates/hardhat-3/01-node-test-runner-viem/contracts/Counter.t.sol

@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.28;
+
+import {Counter} from "./Counter.sol";
+import {Test} from "forge-std/Test.sol";
+
+contract CounterTest is Test {
+  Counter counter;
+
+  function setUp() public {
+    counter = new Counter();
+  }
+
+  function test_InitialValue() public view {
+    require(counter.x() == 0, "Initial value should be 0");
+  }
+
+  function testFuzz_Inc(uint8 x) public {
+    for (uint8 i = 0; i < x; i++) {
+      counter.inc();
+    }
+    require(counter.x() == x, "Value after calling inc x times should be x");
+  }
+
+  function test_IncByZero() public {
+    vm.expectRevert();
+    counter.incBy(0);
+  }
+}

dev/env/node_modules/hardhat/templates/hardhat-3/01-node-test-runner-viem/gitignore

@@ -0,0 +1,20 @@
+# Node modules
+/node_modules
+
+# Compilation output
+/dist
+
+# pnpm deploy output
+/bundle
+
+# Hardhat Build Artifacts
+/artifacts
+
+# Hardhat compilation (v2) support directory
+/cache
+
+# Typechain output
+/types
+
+# Hardhat coverage reports
+/coverage

dev/env/node_modules/hardhat/templates/hardhat-3/01-node-test-runner-viem/hardhat.config.ts

@@ -0,0 +1,38 @@
+import hardhatToolboxViemPlugin from "@nomicfoundation/hardhat-toolbox-viem";
+import { configVariable, defineConfig } from "hardhat/config";
+
+export default defineConfig({
+  plugins: [hardhatToolboxViemPlugin],
+  solidity: {
+    profiles: {
+      default: {
+        version: "0.8.28",
+      },
+      production: {
+        version: "0.8.28",
+        settings: {
+          optimizer: {
+            enabled: true,
+            runs: 200,
+          },
+        },
+      },
+    },
+  },
+  networks: {
+    hardhatMainnet: {
+      type: "edr-simulated",
+      chainType: "l1",
+    },
+    hardhatOp: {
+      type: "edr-simulated",
+      chainType: "op",
+    },
+    sepolia: {
+      type: "http",
+      chainType: "l1",
+      url: configVariable("SEPOLIA_RPC_URL"),
+      accounts: [configVariable("SEPOLIA_PRIVATE_KEY")],
+    },
+  },
+});

dev/env/node_modules/hardhat/templates/hardhat-3/01-node-test-runner-viem/ignition/modules/Counter.ts

@@ -0,0 +1,9 @@
+import { buildModule } from "@nomicfoundation/hardhat-ignition/modules";
+
+export default buildModule("CounterModule", (m) => {
+  const counter = m.contract("Counter");
+
+  m.call(counter, "incBy", [5n]);
+
+  return { counter };
+});

dev/env/node_modules/hardhat/templates/hardhat-3/01-node-test-runner-viem/package.json

@@ -0,0 +1,26 @@
+{
+  "name": "template-node-test-runner-viem",
+  "private": true,
+  "version": "0.0.1",
+  "description": "A TypeScript Hardhat project using Node Test Runner and Viem",
+  "type": "module",
+  "devDependencies": {
+    "hardhat": "workspace:^3.1.10",
+    "@nomicfoundation/hardhat-toolbox-viem": "workspace:^5.0.2",
+    "@nomicfoundation/hardhat-ignition": "workspace:^3.0.8",
+    "@types/node": "^22.8.5",
+    "forge-std": "foundry-rs/forge-std#v1.9.4",
+    "typescript": "~5.8.0",
+    "viem": "^2.43.0"
+  },
+  "peerDependencies": {
+    "@nomicfoundation/hardhat-ignition-viem": "workspace:^3.0.8",
+    "@nomicfoundation/hardhat-keystore": "workspace:^3.0.5",
+    "@nomicfoundation/hardhat-network-helpers": "workspace:^3.0.4",
+    "@nomicfoundation/hardhat-node-test-runner": "workspace:^3.0.9",
+    "@nomicfoundation/hardhat-viem": "workspace:^3.0.3",
+    "@nomicfoundation/hardhat-viem-assertions": "workspace:^3.0.6",
+    "@nomicfoundation/hardhat-verify": "workspace:^3.0.11",
+    "@nomicfoundation/ignition-core": "workspace:^3.0.8"
+  }
+}

dev/env/node_modules/hardhat/templates/hardhat-3/01-node-test-runner-viem/scripts/send-op-tx.ts

@@ -0,0 +1,31 @@
+import { network } from "hardhat";
+
+const { viem } = await network.connect({
+  network: "hardhatOp",
+  chainType: "op",
+});
+
+console.log("Sending transaction using the OP chain type");
+
+const publicClient = await viem.getPublicClient();
+const [senderClient] = await viem.getWalletClients();
+
+console.log("Sending 1 wei from", senderClient.account.address, "to itself");
+
+const l1Gas = await publicClient.estimateL1Gas({
+  account: senderClient.account.address,
+  to: senderClient.account.address,
+  value: 1n,
+});
+
+console.log("Estimated L1 gas:", l1Gas);
+
+console.log("Sending L2 transaction");
+const tx = await senderClient.sendTransaction({
+  to: senderClient.account.address,
+  value: 1n,
+});
+
+await publicClient.waitForTransactionReceipt({ hash: tx });
+
+console.log("Transaction sent successfully");

dev/env/node_modules/hardhat/templates/hardhat-3/01-node-test-runner-viem/test/Counter.ts

@@ -0,0 +1,46 @@
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+
+import { network } from "hardhat";
+
+describe("Counter", async function () {
+  const { viem } = await network.connect();
+  const publicClient = await viem.getPublicClient();
+
+  it("Should emit the Increment event when calling the inc() function", async function () {
+    const counter = await viem.deployContract("Counter");
+
+    await viem.assertions.emitWithArgs(
+      counter.write.inc(),
+      counter,
+      "Increment",
+      [1n],
+    );
+  });
+
+  it("The sum of the Increment events should match the current value", async function () {
+    const counter = await viem.deployContract("Counter");
+    const deploymentBlockNumber = await publicClient.getBlockNumber();
+
+    // run a series of increments
+    for (let i = 1n; i <= 10n; i++) {
+      await counter.write.incBy([i]);
+    }
+
+    const events = await publicClient.getContractEvents({
+      address: counter.address,
+      abi: counter.abi,
+      eventName: "Increment",
+      fromBlock: deploymentBlockNumber,
+      strict: true,
+    });
+
+    // check that the aggregated events match the current value
+    let total = 0n;
+    for (const event of events) {
+      total += event.args.by;
+    }
+
+    assert.equal(total, await counter.read.x());
+  });
+});

dev/env/node_modules/hardhat/templates/hardhat-3/01-node-test-runner-viem/tsconfig.json

@@ -0,0 +1,13 @@
+/* Based on https://github.com/tsconfig/bases/blob/501da2bcd640cf95c95805783e1012b992338f28/bases/node22.json */
+{
+  "compilerOptions": {
+    "lib": ["es2023"],
+    "module": "node16",
+    "target": "es2022",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "moduleResolution": "node16",
+    "outDir": "dist"
+  }
+}

dev/env/node_modules/hardhat/templates/hardhat-3/02-mocha-ethers/README.md

@@ -0,0 +1,57 @@
+# Sample Hardhat 3 Beta Project (`mocha` and `ethers`)
+
+This project showcases a Hardhat 3 Beta project using `mocha` for tests and the `ethers` library for Ethereum interactions.
+
+To learn more about the Hardhat 3 Beta, please visit the [Getting Started guide](https://hardhat.org/docs/getting-started#getting-started-with-hardhat-3). To share your feedback, join our [Hardhat 3 Beta](https://hardhat.org/hardhat3-beta-telegram-group) Telegram group or [open an issue](https://github.com/NomicFoundation/hardhat/issues/new) in our GitHub issue tracker.
+
+## Project Overview
+
+This example project includes:
+
+- A simple Hardhat configuration file.
+- Foundry-compatible Solidity unit tests.
+- TypeScript integration tests using `mocha` and ethers.js
+- Examples demonstrating how to connect to different types of networks, including locally simulating OP mainnet.
+
+## Usage
+
+### Running Tests
+
+To run all the tests in the project, execute the following command:
+
+```shell
+npx hardhat test
+```
+
+You can also selectively run the Solidity or `mocha` tests:
+
+```shell
+npx hardhat test solidity
+npx hardhat test mocha
+```
+
+### Make a deployment to Sepolia
+
+This project includes an example Ignition module to deploy the contract. You can deploy this module to a locally simulated chain or to Sepolia.
+
+To run the deployment to a local chain:
+
+```shell
+npx hardhat ignition deploy ignition/modules/Counter.ts
+```
+
+To run the deployment to Sepolia, you need an account with funds to send the transaction. The provided Hardhat configuration includes a Configuration Variable called `SEPOLIA_PRIVATE_KEY`, which you can use to set the private key of the account you want to use.
+
+You can set the `SEPOLIA_PRIVATE_KEY` variable using the `hardhat-keystore` plugin or by setting it as an environment variable.
+
+To set the `SEPOLIA_PRIVATE_KEY` config variable using `hardhat-keystore`:
+
+```shell
+npx hardhat keystore set SEPOLIA_PRIVATE_KEY
+```
+
+After setting the variable, you can run the deployment with the Sepolia network:
+
+```shell
+npx hardhat ignition deploy --network sepolia ignition/modules/Counter.ts
+```

dev/env/node_modules/hardhat/templates/hardhat-3/02-mocha-ethers/contracts/Counter.sol

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.28;
+
+contract Counter {
+  uint public x;
+
+  event Increment(uint by);
+
+  function inc() public {
+    x++;
+    emit Increment(1);
+  }
+
+  function incBy(uint by) public {
+    require(by > 0, "incBy: increment should be positive");
+    x += by;
+    emit Increment(by);
+  }
+}

dev/env/node_modules/hardhat/templates/hardhat-3/02-mocha-ethers/contracts/Counter.t.sol

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.28;
+
+import {Counter} from "./Counter.sol";
+import {Test} from "forge-std/Test.sol";
+
+// Solidity tests are compatible with foundry, so they
+// use the same syntax and offer the same functionality.
+
+contract CounterTest is Test {
+  Counter counter;
+
+  function setUp() public {
+    counter = new Counter();
+  }
+
+  function test_InitialValue() public view {
+    require(counter.x() == 0, "Initial value should be 0");
+  }
+
+  function testFuzz_Inc(uint8 x) public {
+    for (uint8 i = 0; i < x; i++) {
+      counter.inc();
+    }
+    require(counter.x() == x, "Value after calling inc x times should be x");
+  }
+
+  function test_IncByZero() public {
+    vm.expectRevert();
+    counter.incBy(0);
+  }
+}

dev/env/node_modules/hardhat/templates/hardhat-3/02-mocha-ethers/gitignore

@@ -0,0 +1,20 @@
+# Node modules
+/node_modules
+
+# Compilation output
+/dist
+
+# pnpm deploy output
+/bundle
+
+# Hardhat Build Artifacts
+/artifacts
+
+# Hardhat compilation (v2) support directory
+/cache
+
+# Typechain output
+/types
+
+# Hardhat coverage reports
+/coverage

dev/env/node_modules/hardhat/templates/hardhat-3/02-mocha-ethers/hardhat.config.ts

@@ -0,0 +1,38 @@
+import hardhatToolboxMochaEthersPlugin from "@nomicfoundation/hardhat-toolbox-mocha-ethers";
+import { configVariable, defineConfig } from "hardhat/config";
+
+export default defineConfig({
+  plugins: [hardhatToolboxMochaEthersPlugin],
+  solidity: {
+    profiles: {
+      default: {
+        version: "0.8.28",
+      },
+      production: {
+        version: "0.8.28",
+        settings: {
+          optimizer: {
+            enabled: true,
+            runs: 200,
+          },
+        },
+      },
+    },
+  },
+  networks: {
+    hardhatMainnet: {
+      type: "edr-simulated",
+      chainType: "l1",
+    },
+    hardhatOp: {
+      type: "edr-simulated",
+      chainType: "op",
+    },
+    sepolia: {
+      type: "http",
+      chainType: "l1",
+      url: configVariable("SEPOLIA_RPC_URL"),
+      accounts: [configVariable("SEPOLIA_PRIVATE_KEY")],
+    },
+  },
+});

dev/env/node_modules/hardhat/templates/hardhat-3/02-mocha-ethers/ignition/modules/Counter.ts

@@ -0,0 +1,9 @@
+import { buildModule } from "@nomicfoundation/hardhat-ignition/modules";
+
+export default buildModule("CounterModule", (m) => {
+  const counter = m.contract("Counter");
+
+  m.call(counter, "incBy", [5n]);
+
+  return { counter };
+});

dev/env/node_modules/hardhat/templates/hardhat-3/02-mocha-ethers/package.json

@@ -0,0 +1,34 @@
+{
+  "name": "template-mocha-ethers",
+  "private": true,
+  "version": "0.0.1",
+  "description": "A TypeScript Hardhat project using Mocha and Ethers.js",
+  "type": "module",
+  "devDependencies": {
+    "hardhat": "workspace:^3.1.10",
+    "@nomicfoundation/hardhat-toolbox-mocha-ethers": "workspace:^3.0.3",
+    "@nomicfoundation/hardhat-ethers": "workspace:^4.0.5",
+    "@nomicfoundation/hardhat-ignition": "workspace:^3.0.8",
+    "@types/chai": "^5.2.3",
+    "@types/chai-as-promised": "^8.0.1",
+    "@types/mocha": ">=10.0.10",
+    "@types/node": "^22.8.5",
+    "chai": "^6.2.2",
+    "ethers": "^6.14.0",
+    "forge-std": "foundry-rs/forge-std#v1.9.4",
+    "mocha": "^11.0.0",
+    "typescript": "~5.8.0"
+  },
+  "peerDependencies": {
+    "@nomicfoundation/hardhat-ethers": "workspace:^4.0.5",
+    "@nomicfoundation/hardhat-ethers-chai-matchers": "workspace:^3.0.3",
+    "@nomicfoundation/hardhat-ignition": "workspace:^3.0.8",
+    "@nomicfoundation/hardhat-ignition-ethers": "workspace:^3.0.8",
+    "@nomicfoundation/hardhat-keystore": "workspace:^3.0.5",
+    "@nomicfoundation/hardhat-mocha": "workspace:^3.0.11",
+    "@nomicfoundation/hardhat-network-helpers": "workspace:^3.0.4",
+    "@nomicfoundation/hardhat-typechain": "workspace:^3.0.3",
+    "@nomicfoundation/hardhat-verify": "workspace:^3.0.11",
+    "@nomicfoundation/ignition-core": "workspace:^3.0.8"
+  }
+}

dev/env/node_modules/hardhat/templates/hardhat-3/02-mocha-ethers/scripts/send-op-tx.ts

@@ -0,0 +1,22 @@
+import { network } from "hardhat";
+
+const { ethers } = await network.connect({
+  network: "hardhatOp",
+  chainType: "op",
+});
+
+console.log("Sending transaction using the OP chain type");
+
+const [sender] = await ethers.getSigners();
+
+console.log("Sending 1 wei from", sender.address, "to itself");
+
+console.log("Sending L2 transaction");
+const tx = await sender.sendTransaction({
+  to: sender.address,
+  value: 1n,
+});
+
+await tx.wait();
+
+console.log("Transaction sent successfully");

dev/env/node_modules/hardhat/templates/hardhat-3/02-mocha-ethers/test/Counter.ts

@@ -0,0 +1,36 @@
+import { expect } from "chai";
+import { network } from "hardhat";
+
+const { ethers } = await network.connect();
+
+describe("Counter", function () {
+  it("Should emit the Increment event when calling the inc() function", async function () {
+    const counter = await ethers.deployContract("Counter");
+
+    await expect(counter.inc()).to.emit(counter, "Increment").withArgs(1n);
+  });
+
+  it("The sum of the Increment events should match the current value", async function () {
+    const counter = await ethers.deployContract("Counter");
+    const deploymentBlockNumber = await ethers.provider.getBlockNumber();
+
+    // run a series of increments
+    for (let i = 1; i <= 10; i++) {
+      await counter.incBy(i);
+    }
+
+    const events = await counter.queryFilter(
+      counter.filters.Increment(),
+      deploymentBlockNumber,
+      "latest",
+    );
+
+    // check that the aggregated events match the current value
+    let total = 0n;
+    for (const event of events) {
+      total += event.args.by;
+    }
+
+    expect(await counter.x()).to.equal(total);
+  });
+});

dev/env/node_modules/hardhat/templates/hardhat-3/02-mocha-ethers/tsconfig.json

@@ -0,0 +1,13 @@
+/* Based on https://github.com/tsconfig/bases/blob/501da2bcd640cf95c95805783e1012b992338f28/bases/node22.json */
+{
+  "compilerOptions": {
+    "lib": ["es2023"],
+    "module": "node16",
+    "target": "es2022",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "moduleResolution": "node16",
+    "outDir": "dist"
+  }
+}

dev/env/node_modules/hardhat/templates/hardhat-3/03-minimal/README.md

@@ -0,0 +1,7 @@
+# Sample Hardhat 3 Beta Project (minimal)
+
+This project has a minimal setup of Hardhat 3 Beta, without any plugins.
+
+## What's included?
+
+The project includes native support for TypeScript, Hardhat scripts, tasks, and support for Solidity compilation and tests.

dev/env/node_modules/hardhat/templates/hardhat-3/03-minimal/gitignore

@@ -0,0 +1,20 @@
+# Node modules
+/node_modules
+
+# Compilation output
+/dist
+
+# pnpm deploy output
+/bundle
+
+# Hardhat Build Artifacts
+/artifacts
+
+# Hardhat compilation (v2) support directory
+/cache
+
+# Typechain output
+/types
+
+# Hardhat coverage reports
+/coverage

dev/env/node_modules/hardhat/templates/hardhat-3/03-minimal/hardhat.config.ts

@@ -0,0 +1,7 @@
+import { defineConfig } from "hardhat/config";
+
+export default defineConfig({
+  solidity: {
+    version: "0.8.28",
+  },
+});

dev/env/node_modules/hardhat/templates/hardhat-3/03-minimal/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "template-minimal",
+  "private": true,
+  "version": "0.0.1",
+  "description": "A minimal Hardhat project",
+  "type": "module",
+  "devDependencies": {
+    "hardhat": "workspace:^3.1.10",
+    "@types/node": "^22.8.5",
+    "typescript": "~5.8.0"
+  }
+}

dev/env/node_modules/hardhat/templates/hardhat-3/03-minimal/tsconfig.json

@@ -0,0 +1,13 @@
+/* Based on https://github.com/tsconfig/bases/blob/501da2bcd640cf95c95805783e1012b992338f28/bases/node22.json */
+{
+  "compilerOptions": {
+    "lib": ["es2023"],
+    "module": "node16",
+    "target": "es2022",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "moduleResolution": "node16",
+    "outDir": "dist"
+  }
+}