refactor: flatten CLI directory structure - remove 'box in a box'

BEFORE:
/opt/aitbc/cli/
├── aitbc_cli/                    # Python package (box in a box)
│   ├── commands/
│   ├── main.py
│   └── ...
├── setup.py

AFTER:
/opt/aitbc/cli/                    # Flat structure
├── commands/                      # Direct access
├── main.py                        # Direct access
├── auth/
├── config/
├── core/
├── models/
├── utils/
├── plugins.py
└── setup.py

CHANGES MADE:
- Moved all files from aitbc_cli/ to cli/ root
- Fixed all relative imports (from . to absolute imports)
- Updated setup.py entry point: aitbc_cli.main → main
- Added CLI directory to Python path in entry script
- Simplified deployment.py to remove dependency on deleted core.deployment
- Fixed import paths in all command files
- Recreated virtual environment with new structure

BENEFITS:
- Eliminated 'box in a box' nesting
- Simpler directory structure
- Direct access to all modules
- Cleaner imports
- Easier maintenance and development
- CLI works with both 'python main.py' and 'aitbc' commands

cli/auth/__init__.py

@@ -0,0 +1,70 @@
+"""Authentication and credential management for AITBC CLI"""
+
+import keyring
+import os
+from typing import Optional, Dict
+from utils import success, error, warning
+
+
+class AuthManager:
+    """Manages authentication credentials using secure keyring storage"""
+    
+    SERVICE_NAME = "aitbc-cli"
+    
+    def __init__(self):
+        self.keyring = keyring.get_keyring()
+    
+    def store_credential(self, name: str, api_key: str, environment: str = "default"):
+        """Store an API key securely"""
+        try:
+            key = f"{environment}_{name}"
+            self.keyring.set_password(self.SERVICE_NAME, key, api_key)
+            success(f"Credential '{name}' stored for environment '{environment}'")
+        except Exception as e:
+            error(f"Failed to store credential: {e}")
+    
+    def get_credential(self, name: str, environment: str = "default") -> Optional[str]:
+        """Retrieve an API key"""
+        try:
+            key = f"{environment}_{name}"
+            return self.keyring.get_password(self.SERVICE_NAME, key)
+        except Exception as e:
+            warning(f"Failed to retrieve credential: {e}")
+            return None
+    
+    def delete_credential(self, name: str, environment: str = "default"):
+        """Delete an API key"""
+        try:
+            key = f"{environment}_{name}"
+            self.keyring.delete_password(self.SERVICE_NAME, key)
+            success(f"Credential '{name}' deleted for environment '{environment}'")
+        except Exception as e:
+            error(f"Failed to delete credential: {e}")
+    
+    def list_credentials(self, environment: str = None) -> Dict[str, str]:
+        """List all stored credentials (without showing the actual keys)"""
+        # Note: keyring doesn't provide a direct way to list all keys
+        # This is a simplified version that checks for common credential names
+        credentials = []
+        envs = [environment] if environment else ["default", "dev", "staging", "prod"]
+        names = ["client", "miner", "admin"]
+        
+        for env in envs:
+            for name in names:
+                key = f"{env}_{name}"
+                if self.get_credential(name, env):
+                    credentials.append(f"{name}@{env}")
+        
+        return credentials
+    
+    def store_env_credential(self, name: str):
+        """Store credential from environment variable"""
+        env_var = f"{name.upper()}_API_KEY"
+        api_key = os.getenv(env_var)
+        
+        if not api_key:
+            error(f"Environment variable {env_var} not set")
+            return False
+        
+        self.store_credential(name, api_key)
+        return True