RepoAssignment now always grants LicensedReadOnly for download
paths (/releases/, /archive/) on licensed repos. The actual
download gating (none/prerelease/all) is enforced by
CheckDownloadGating in the handler.
Previously only download_gating=none allowed anonymous access.
Now prerelease gating also allows through (CheckDownloadGating
blocks non-stable downloads without a key).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>