The 3.10.0 milestone was about making the advertised smoke pack trustworthy enough to act like a real release gate. The main drift was in the repro-plus-fix scenario: the recipe docs were SDK-first, but the smoke still shelled out to CLI patch apply and asserted a human summary string.\n\nSwitch the smoke runner to use the structured SDK patch flow directly, remove the harness-only CLI dependency, and tighten the fake smoke tests so they prove the same structured path the docs recommend. This keeps smoke failures tied to real user-facing regressions instead of human-output formatting drift.\n\nPromote make smoke-use-cases as the trustworthy guest-backed verification path in the top-level docs, bump the release surface to 3.10.0, and mark the roadmap milestone done.\n\nValidation:\n- uv lock\n- UV_CACHE_DIR=.uv-cache uv run pytest --no-cov tests/test_workspace_use_case_smokes.py\n- UV_CACHE_DIR=.uv-cache make check\n- UV_CACHE_DIR=.uv-cache make dist-check\n- USE_CASE_ENVIRONMENT=debian:12 UV_CACHE_DIR=.uv-cache make smoke-use-cases