feat: implement role-based configuration system for CLI with automatic API key management

- Add role detection to command groups (admin, client, miner, blockchain)
- Load role-specific config files (~/.aitbc/{role}-config.yaml)
- Add role field to Config class with environment variable support
- Implement automatic role detection from invoked subcommand
- Add development mode API key bypass for testing (APP_ENV=dev)
- Update CLI checklist with role-based configuration documentation
- Add configuration override priority and

cli/aitbc_cli/commands/admin.py

@@ -8,9 +8,12 @@ from ..utils import output, error, success
 
 
 @click.group()
-def admin():
+@click.pass_context
+def admin(ctx):
     """System administration commands"""
-    pass
+    # Set role for admin commands
+    ctx.ensure_object(dict)
+    ctx.parent.detected_role = 'admin'
 
 
 @admin.command()