v1.27.6

Changed

• Release workflow's "Wait for PyPI propagation" step now probes
  with pip download --no-deps against the resolver path the
  docker build is about to take, instead of a curl against the
  JSON metadata endpoint. The old probe reported 200 well before
  pip's CDN node could actually resolve the wheel, causing
  back-to-back publish-docker failures on v1.27.2, v1.27.4, and
  v1.27.5 even at a 120s budget. The new probe polls at 10s
  intervals for up to 10 minutes, succeeding only when a real pip download resolves and fetches the wheel; until then the
  workflow logs one heartbeat per attempt so operators watching
  the run can see the propagation status. No operator-facing
  workflow shape change.