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/@nomicfoundation/hardhat-errors/README.md

@@ -0,0 +1,12 @@
+# hardhat-errors
+
+> ⚠️ This package is an internal Hardhat component and it's not meant to be used directly.
+
+This packages has the definition of the error classes used by Hardhat, and the list of possible errors.
+
+This module exports:
+
+1. The error class `HardhatError`, which has a static field `ERRORS`, with the different `ErrorDescriptors` that it accepts.
+2. The error class `HardhatPluginError`, which is the recommended way to handle errors in Hardhat plugins. For convenience, it is re-exported from `@nomicfoundation/hardhat/plugins`. Plugin developers should import it from this path.
+3. The interface `ErrorDescriptor`.
+4. The assertion helper `assertHardhatInvariant`.