Start v0.6.1 development - #38

Summary

• record the completed v0.6.0 annotated-tag/OIDC/PyPI/GitHub Release evidence
• advance development to 0.6.1.dev0
• mark the v0.6 quality record released and regenerate PYPI.md against main

Public release verification

• tag v0.6.0 -> 6cfbdbb7bbf5c6042def4cf154bfe3c3b6530eea
• release workflow: https://github.com/DaoyuanLi2816/mini-verl/actions/runs/30796058250
• wheel SHA-256: e5fbb99bf410c27d22d6959f9599dfa4fbac2e940dac63f55c9676f68264abd1
• sdist SHA-256: 2e1d85556875f6d23152220897ba919d8b82bda35c5c78fd48efffa7ec22909d
• PyPI provenance exposes one Trusted Publisher attestation bundle per distribution
• a clean Windows Python 3.10 install from https://pypi.org/simple reports miniverl 0.6.0; core doctor --json passes with torch absent

Validation

• Ruff check and format check
• mypy: 103 source files
• Markdown/link and generated PyPI checks
• full non-GPU/non-network suite: 1548 passed, 6 deselected, 85.53% branch coverage
• packaging/release focused suite: 111 passed
• wheel and sdist build; Twine check
• frozen calculator JSON remains SHA-256 53fc1d4d5b7adee09618d77ad62d4086ba56b78569832d6fc7c3bcd5c2695bbc