Add BUILD-VERIFIED packaging check (no publish)

[alex-16moro]

Summary

Add tools/release_check.py so a library checkout can prove a merged change produces an installable wheel. Verdict is BUILD-VERIFIED / PACKAGING-ELIGIBLE or NOT PACKAGING-ELIGIBLE. The wrapper does not publish, tag, twine-upload, or run make pre-release.

Steps, in order, against the fork checkout:

1. pytest tests/others/test_dependencies.py -q
2. python -m build --wheel (install build if needed; wipe dist/ first; record the exact wheel path)
3. pip install --force-reinstall <that wheel> then env -u PYTHONPATH import the new public export and assert diffusers.__file__ is under site-packages
4. Restore pip install -e . so the checkout stays usable

--object selects the export; if omitted, the new symbol is detected from src/diffusers/__init__.py vs origin/main (or origin/main~1 when the tree already matches a just-landed merge). Advisories (changelog, semver, TODO(engineer) in step()) are FYI and never gate.

GrokBot DevOps gains a Packaging section fed by --release-json from that report. It does not run python -m build. If the JSON is absent, the section prints not wired.

projections/devops/ci-gate.md is regenerated from tools/build_projections.py (make build). dist/ is gitignored.

Convention gate

• make test (63 tests)
• make drift (generated ci-gate.md matches the generator)

Tests run

env -u PYTHONPATH python3 -m unittest discover -s tests -t . -v
env -u PYTHONPATH make drift

Fork VERIFY on the PR #20 checkout (cursor/pndm-lite-scaffold-2ce3, already landed on origin/main):

python ramp-kit/tools/release_check.py --json
# object: PNDMLiteScheduler (detected, not hardcoded)
# dependency_contract: 4 passed
# wheel: dist/diffusers-0.41.0.dev0-py3-none-any.whl
# import: /home/ubuntu/.local/lib/python3.12/site-packages/diffusers/__init__.py
# verdict: BUILD-VERIFIED / PACKAGING-ELIGIBLE
# advisories: changelog, semver, step() TODO(engineer) — not blocking

python tools/grokbot_sim.py --role devops --release-json <report.json>
# Packaging section quotes that verdict + site-packages __file__
# without --release-json: "packaging check not wired"

Editable install restored (pip install -e .). dist/ is gitignored and not committed.

Human judgment (not the gate)

• This is a packaging wrapper around the library's own pytest / python -m build, not a new product.
• Scaffold step() math stays TODO(engineer).