py.typed is in the published wheel but missing from the sdist — source installs lose PEP 561 typing #968

The published detect-secrets 1.5.0 wheel contains detect_secrets/py.typed, but a wheel built from the published sdist does not — so anyone installing from source (distros, --no-binary, platforms without wheels) silently loses type-checking support. (#579 added py.typed to the package, but the sdist doesn't ship it.)

Fix is one line: ensure py.typed is included in the sdist (MANIFEST.in or package-data).

Found by a wheel/sdist divergence census of popular PyPI packages (wheelproof, results/divergence.md); self-check with wheelproof divcheck --package <name>. Verified twice in clean python:3.12 containers with exact file-list agreement.