feat: Hardhat plugin package for seamless integration with Hardhat workflows

examples/hardhat-project/.gitignore

@@ -0,0 +1,6 @@
+node_modules/
+cache/
+artifacts/
+typechain-types/
+audit.md
+coverage/

examples/hardhat-project/README.md

@@ -0,0 +1,44 @@
+# ChainProof Hardhat Example
+
+Example Hardhat project demonstrating `@chainproof/hardhat-plugin`.
+
+## Setup
+
+From the repository root:
+
+```bash
+npm install
+npm run build
+cd examples/hardhat-project
+npm install
+```
+
+## Tasks
+
+```bash
+# Full audit
+npx hardhat chainproof
+
+# Fast CI check (exit code 1 on critical/high)
+npx hardhat chainproof:check
+
+# Generate report file
+npx hardhat chainproof:report --format markdown --output audit.md
+```
+
+## Compile hook
+
+Enable automatic scans after compile in `hardhat.config.ts`:
+
+```typescript
+chainproof: {
+  runOnCompile: true,
+  failOnCompile: false,
+}
+```
+
+Then run `npx hardhat compile`.
+
+## Test footer
+
+When running tests on the Hardhat Network (`npx hardhat test`), ChainProof prints a security summary footer after test output.

examples/hardhat-project/contracts/VulnerableToken.sol

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+/**
+ * @title VulnerableToken
+ * @notice Intentionally vulnerable contract for ChainProof Hardhat plugin demos.
+ */
+contract VulnerableToken {
+    address public owner;
+    mapping(address => uint256) public balances;
+
+    constructor() {
+        owner = msg.sender;
+    }
+
+    modifier onlyOwner() {
+        require(tx.origin == owner, "Not owner");
+        _;
+    }
+
+    function deposit() external payable {
+        balances[msg.sender] += msg.value;
+    }
+
+    function withdraw(uint256 amount) external {
+        require(balances[msg.sender] >= amount, "Insufficient balance");
+        (bool success, ) = msg.sender.call{value: amount}("");
+        require(success, "Transfer failed");
+        balances[msg.sender] -= amount;
+    }
+
+    function mint(address to, uint256 amount) external onlyOwner {
+        balances[to] += amount;
+    }
+}

examples/hardhat-project/hardhat.config.ts

@@ -0,0 +1,17 @@
+import type { HardhatUserConfig } from "hardhat/config";
+import "@nomicfoundation/hardhat-toolbox";
+import "@chainproof/hardhat-plugin";
+
+const config: HardhatUserConfig = {
+  solidity: "0.8.20",
+  chainproof: {
+    targets: ["contracts/"],
+    minSeverity: "high",
+    useSlither: false,
+    useLLM: false,
+    runOnCompile: false,
+    failOnCompile: false,
+  },
+};
+
+export default config;