make test was dominated by teardown-heavy workspace integration tests, not by coverage overhead. Service shutdown was treating zombie processes as live, which forced repeated timeout waits, and one shell test was leaving killpg monkeypatched during cleanup, which made shell close paths burn the full wait budget.\n\nTreat Linux zombie pids as stopped in the workspace manager so service teardown completes promptly. Restore the real killpg implementation before shell test cleanup so the shell close path no longer pays the artificial timeout. Also isolate sys.argv in the runtime-network-check main() test so parallel pytest flags do not leak into argparse-based tests.\n\nAdd pytest-xdist to the dev environment and run make test with pytest -n auto by default so available cores are used automatically during local iteration.\n\nValidation:\n- uv lock\n- targeted hot-spot pytest rerun after the fix dropped the worst tests from roughly 10-21s each to sub-second timings\n- UV_CACHE_DIR=.uv-cache make check\n- UV_CACHE_DIR=.uv-cache make dist-check
Turn the stable workspace surface into five documented, runnable stories with a shared guest-backed smoke runner, new docs/use-cases recipes, and Make targets for cold-start validation, repro/fix loops, parallel workspaces, untrusted inspection, and review/eval workflows.
Bump the package and catalog surface to 3.6.0, update the main docs to point users from the stable workspace walkthrough into the recipe index and smoke packs, and mark the 3.6.0 roadmap milestone done.
Fix a regression uncovered by the real parallel-workspaces smoke: workspace_file_read must not bump last_activity_at. Verified with uv lock, UV_CACHE_DIR=.uv-cache make check, UV_CACHE_DIR=.uv-cache make dist-check, and USE_CASE_ENVIRONMENT=debian:12 UV_CACHE_DIR=.uv-cache make smoke-use-cases.
