Two follow-ups to the 7.0.239 release CI run:

1. release-on-maven-central.yml: only poll Maven Central after the
   central-publishing plugin actually reports failure. The 7.0.239
   deploy validated cleanly but my earlier verify step demanded the
   artifact be on repo1.maven.org within 5 minutes; Sonatype Central
   to repo1 propagation can take much longer than that. The polling
   step now runs only on plugin failure (the false-positive recovery
   path), with a 30-minute timeout, and an explicit fail step asserts
   the release truly completed.

2. initializr-cn1-version-pr.yml: drop the tag-push trigger and wait
   for developer-guide.pdf on the release before opening the PR.
   The PR's website-docs build calls update_developer_guide_redirect.sh
   which fetches that asset from the latest release; it is attached
   by developer-guide-docs.yml a few minutes after release publish,
   so opening the PR on tag push raced ahead of the asset upload.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>