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/token/ERC6909/extensions/draft-ERC6909ContentURI.sol

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v5.3.0) (token/ERC6909/extensions/draft-ERC6909ContentURI.sol)
+
+pragma solidity ^0.8.20;
+
+import {ERC6909} from "../draft-ERC6909.sol";
+import {IERC6909ContentURI} from "../../../interfaces/draft-IERC6909.sol";
+
+/**
+ * @dev Implementation of the Content URI extension defined in ERC6909.
+ */
+contract ERC6909ContentURI is ERC6909, IERC6909ContentURI {
+    string private _contractURI;
+    mapping(uint256 id => string) private _tokenURIs;
+
+    /// @dev Event emitted when the contract URI is changed. See https://eips.ethereum.org/EIPS/eip-7572[ERC-7572] for details.
+    event ContractURIUpdated();
+
+    /// @dev See {IERC1155-URI}
+    event URI(string value, uint256 indexed id);
+
+    /// @inheritdoc IERC6909ContentURI
+    function contractURI() public view virtual override returns (string memory) {
+        return _contractURI;
+    }
+
+    /// @inheritdoc IERC6909ContentURI
+    function tokenURI(uint256 id) public view virtual override returns (string memory) {
+        return _tokenURIs[id];
+    }
+
+    /**
+     * @dev Sets the {contractURI} for the contract.
+     *
+     * Emits a {ContractURIUpdated} event.
+     */
+    function _setContractURI(string memory newContractURI) internal virtual {
+        _contractURI = newContractURI;
+
+        emit ContractURIUpdated();
+    }
+
+    /**
+     * @dev Sets the {tokenURI} for a given token of type `id`.
+     *
+     * Emits a {URI} event.
+     */
+    function _setTokenURI(uint256 id, string memory newTokenURI) internal virtual {
+        _tokenURIs[id] = newTokenURI;
+
+        emit URI(newTokenURI, id);
+    }
+}

dev/env/node_modules/@openzeppelin/contracts/token/ERC6909/extensions/draft-ERC6909Metadata.sol

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v5.3.0) (token/ERC6909/extensions/draft-ERC6909Metadata.sol)
+
+pragma solidity ^0.8.20;
+
+import {ERC6909} from "../draft-ERC6909.sol";
+import {IERC6909Metadata} from "../../../interfaces/draft-IERC6909.sol";
+
+/**
+ * @dev Implementation of the Metadata extension defined in ERC6909. Exposes the name, symbol, and decimals of each token id.
+ */
+contract ERC6909Metadata is ERC6909, IERC6909Metadata {
+    struct TokenMetadata {
+        string name;
+        string symbol;
+        uint8 decimals;
+    }
+
+    mapping(uint256 id => TokenMetadata) private _tokenMetadata;
+
+    /// @dev The name of the token of type `id` was updated to `newName`.
+    event ERC6909NameUpdated(uint256 indexed id, string newName);
+
+    /// @dev The symbol for the token of type `id` was updated to `newSymbol`.
+    event ERC6909SymbolUpdated(uint256 indexed id, string newSymbol);
+
+    /// @dev The decimals value for token of type `id` was updated to `newDecimals`.
+    event ERC6909DecimalsUpdated(uint256 indexed id, uint8 newDecimals);
+
+    /// @inheritdoc IERC6909Metadata
+    function name(uint256 id) public view virtual override returns (string memory) {
+        return _tokenMetadata[id].name;
+    }
+
+    /// @inheritdoc IERC6909Metadata
+    function symbol(uint256 id) public view virtual override returns (string memory) {
+        return _tokenMetadata[id].symbol;
+    }
+
+    /// @inheritdoc IERC6909Metadata
+    function decimals(uint256 id) public view virtual override returns (uint8) {
+        return _tokenMetadata[id].decimals;
+    }
+
+    /**
+     * @dev Sets the `name` for a given token of type `id`.
+     *
+     * Emits an {ERC6909NameUpdated} event.
+     */
+    function _setName(uint256 id, string memory newName) internal virtual {
+        _tokenMetadata[id].name = newName;
+
+        emit ERC6909NameUpdated(id, newName);
+    }
+
+    /**
+     * @dev Sets the `symbol` for a given token of type `id`.
+     *
+     * Emits an {ERC6909SymbolUpdated} event.
+     */
+    function _setSymbol(uint256 id, string memory newSymbol) internal virtual {
+        _tokenMetadata[id].symbol = newSymbol;
+
+        emit ERC6909SymbolUpdated(id, newSymbol);
+    }
+
+    /**
+     * @dev Sets the `decimals` for a given token of type `id`.
+     *
+     * Emits an {ERC6909DecimalsUpdated} event.
+     */
+    function _setDecimals(uint256 id, uint8 newDecimals) internal virtual {
+        _tokenMetadata[id].decimals = newDecimals;
+
+        emit ERC6909DecimalsUpdated(id, newDecimals);
+    }
+}

dev/env/node_modules/@openzeppelin/contracts/token/ERC6909/extensions/draft-ERC6909TokenSupply.sol

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v5.3.0) (token/ERC6909/extensions/draft-ERC6909TokenSupply.sol)
+
+pragma solidity ^0.8.20;
+
+import {ERC6909} from "../draft-ERC6909.sol";
+import {IERC6909TokenSupply} from "../../../interfaces/draft-IERC6909.sol";
+
+/**
+ * @dev Implementation of the Token Supply extension defined in ERC6909.
+ * Tracks the total supply of each token id individually.
+ */
+contract ERC6909TokenSupply is ERC6909, IERC6909TokenSupply {
+    mapping(uint256 id => uint256) private _totalSupplies;
+
+    /// @inheritdoc IERC6909TokenSupply
+    function totalSupply(uint256 id) public view virtual override returns (uint256) {
+        return _totalSupplies[id];
+    }
+
+    /// @dev Override the `_update` function to update the total supply of each token id as necessary.
+    function _update(address from, address to, uint256 id, uint256 amount) internal virtual override {
+        super._update(from, to, id, amount);
+
+        if (from == address(0)) {
+            _totalSupplies[id] += amount;
+        }
+        if (to == address(0)) {
+            unchecked {
+                // amount <= _balances[from][id] <= _totalSupplies[id]
+                _totalSupplies[id] -= amount;
+            }
+        }
+    }
+}