592e5e2191
- Added interactive shell console subcommand to coding-agent CLI with support for working directory, timeout, and snapshot configuration. - Added cancellation token support to ExecutionContext and ExecutionParameters for graceful shell execution interruption. - Implemented cancellation checks throughout AST execution pipeline (Program, CompoundList, AndOrList, Pipeline, and all command types) to enable responsive interruption. - Replaced process tracking mechanism with tokio_util CancellationToken for improved async cancellation handling. - Added tokio-util 0.7.16 dependency to pi-natives crate for cancellation token support.