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/cli_env/lib64/python3.13/site-packages/keyring/credentials.py

@@ -0,0 +1,85 @@
+from __future__ import annotations
+
+import abc
+import os
+
+
+class Credential(metaclass=abc.ABCMeta):
+    """Abstract class to manage credentials"""
+
+    @abc.abstractproperty
+    def username(self) -> str: ...
+
+    @abc.abstractproperty
+    def password(self) -> str: ...
+
+    def _vars(self) -> dict[str, str]:
+        return dict(username=self.username, password=self.password)
+
+
+class SimpleCredential(Credential):
+    """Simple credentials implementation"""
+
+    def __init__(self, username: str, password: str):
+        self._username = username
+        self._password = password
+
+    @property
+    def username(self) -> str:
+        return self._username
+
+    @property
+    def password(self) -> str:
+        return self._password
+
+
+class AnonymousCredential(SimpleCredential):
+    def __init__(self, password: str):
+        self._password = password
+
+    @property
+    def username(self) -> str:
+        raise ValueError("Anonymous credential has no username")
+
+    def _vars(self) -> dict[str, str]:
+        return dict(password=self.password)
+
+
+class EnvironCredential(Credential):
+    """
+    Source credentials from environment variables.
+
+    Actual sourcing is deferred until requested.
+
+    Supports comparison by equality.
+
+    >>> e1 = EnvironCredential('a', 'b')
+    >>> e2 = EnvironCredential('a', 'b')
+    >>> e3 = EnvironCredential('a', 'c')
+    >>> e1 == e2
+    True
+    >>> e2 == e3
+    False
+    """
+
+    def __init__(self, user_env_var: str, pwd_env_var: str):
+        self.user_env_var = user_env_var
+        self.pwd_env_var = pwd_env_var
+
+    def __eq__(self, other: object) -> bool:
+        return vars(self) == vars(other)
+
+    def _get_env(self, env_var: str) -> str:
+        """Helper to read an environment variable"""
+        value = os.environ.get(env_var)
+        if not value:
+            raise ValueError(f'Missing environment variable:{env_var}')
+        return value
+
+    @property
+    def username(self) -> str:
+        return self._get_env(self.user_env_var)
+
+    @property
+    def password(self) -> str:
+        return self._get_env(self.pwd_env_var)