Add ds4-agent as a native terminal coding agent with session KV storage, DSML tool execution, edit/read/search/write/list/bash tools, async bash jobs, compaction support, history replay, and a linenoise-based interactive UI. The agent defaults to CRC-guarded edits, streams tool visualization, ignores tool calls emitted inside thinking, improves bash output observations for long-running commands, and styles prompts, spacing, and prefill progress for interactive use.