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/@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol

@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v5.2.0) (proxy/ERC1967/ERC1967Proxy.sol)
+
+pragma solidity ^0.8.22;
+
+import {Proxy} from "../Proxy.sol";
+import {ERC1967Utils} from "./ERC1967Utils.sol";
+
+/**
+ * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
+ * implementation address that can be changed. This address is stored in storage in the location specified by
+ * https://eips.ethereum.org/EIPS/eip-1967[ERC-1967], so that it doesn't conflict with the storage layout of the
+ * implementation behind the proxy.
+ */
+contract ERC1967Proxy is Proxy {
+    /**
+     * @dev Initializes the upgradeable proxy with an initial implementation specified by `implementation`.
+     *
+     * If `_data` is nonempty, it's used as data in a delegate call to `implementation`. This will typically be an
+     * encoded function call, and allows initializing the storage of the proxy like a Solidity constructor.
+     *
+     * Requirements:
+     *
+     * - If `data` is empty, `msg.value` must be zero.
+     */
+    constructor(address implementation, bytes memory _data) payable {
+        ERC1967Utils.upgradeToAndCall(implementation, _data);
+    }
+
+    /**
+     * @dev Returns the current implementation address.
+     *
+     * TIP: To get this value clients can read directly from the storage slot shown below (specified by ERC-1967) using
+     * the https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
+     * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
+     */
+    function _implementation() internal view virtual override returns (address) {
+        return ERC1967Utils.getImplementation();
+    }
+}