Remove the remaining shell glue from the canonical CLI workspace flows so users can hand off IDs and host-authored text files directly.
Add --id-only on workspace create and shell open, plus --text-file and --patch-file for workspace file write and patch apply, while keeping the underlying SDK, MCP, and backend behavior unchanged.
Update the top walkthroughs, contract docs, roadmap status, and use-case smoke runner to use the new shortcuts, and verify the milestone with uv lock, make check, make dist-check, focused CLI tests, and a real guest-backed smoke for create, file write, patch apply, and shell open/read.