CAIN-42 SDK installability evidence  (installability-2026-10-01)
=================================================================
Generated 2026-10-01T02:15:33+00:00.

WHAT THIS PROVES
  Both distributions an engineer is told to install build and install into a clean
  virtual environment, and import and run from the installed wheel (not from the
  source checkout):
    * `cain-trust`  -> import cain, import cain_sdk, `cain` console entry point
    * `cainstudio` (sdk/python) -> import cainstudio, `cainstudio` console entry point

  Result: PASS — 19/19 checks.
  Checks:
    - [PASS] packaging inputs copied
    - [PASS] wheel builds
    - [PASS] wheel ships the cain package
    - [PASS] wheel ships the packaged substrate
    - [PASS] wheel ships cain_sdk
    - [PASS] wheel ships the trust roots
    - [PASS] wheel declares the cain entry point
    - [PASS] virtual environment created
    - [PASS] wheel installs cleanly
    - [PASS] `import cain` works after install (from the wheel, not the checkout)
    - [PASS] `import cain_sdk` works after install
    - [PASS] `cain --help` runs after install
    - [PASS] client-SDK packaging inputs copied
    - [PASS] cainstudio wheel builds
    - [PASS] cainstudio wheel ships the package
    - [PASS] cainstudio wheel declares its CLI
    - [PASS] cainstudio installs cleanly
    - [PASS] `import cainstudio` works after install
    - [PASS] `cainstudio --help` runs after install

REPRODUCE
  python3 scripts/verify_installability.py
  # copies the packaging inputs to a temp dir, builds each wheel, creates one venv,
  # installs each with --no-deps, then checks imports and the console entry points
  # from a neutral working directory (so the checkout cannot shadow the install).

LIMITS
  - This proves the wheels install and import; it does NOT prove runtime behaviour
    end to end (that is covered by the test suite and the other bundles).
  - The venv reuses system site-packages for dependencies; a fully offline cold
    install of every dependency is not exercised here.
  - Publication to PyPI is not performed by this check; it verifies the artifacts
    that would be published.