Implement sudo support across terminal environments

- Added support for sudo commands in local, Docker, Singularity, and SSH environments by introducing the `SUDO_PASSWORD` environment variable.
- Updated terminal tool configurations in `.env.example` and `cli-config.yaml.example` to document the new sudo functionality.
- Enhanced the command execution process to handle sudo commands gracefully, preventing hangs on interactive prompts and providing clear error messages when no password is configured.
- Updated `README.md` to include instructions for using sudo support and SSH backend configuration.
- Revised `TODO.md` to reflect the completion of the sudo feature and outline future enhancements.

cli.py

@@ -134,6 +134,8 @@ def load_cli_config() -> Dict[str, Any]:
         "ssh_user": "TERMINAL_SSH_USER",
         "ssh_port": "TERMINAL_SSH_PORT",
         "ssh_key": "TERMINAL_SSH_KEY",
+        # Sudo support (works with all backends)
+        "sudo_password": "SUDO_PASSWORD",
     }
     
     # CLI config overrides .env for terminal settings