Advance development to 0.9.1.dev0 - #74

Summary

• record the verified v0.9.0 OIDC publication, public hashes, GitHub Release, and stable documentation deployment
• advance the canonical development version to 0.9.1.dev0
• keep tag pushes in the docs build and visual gate without requesting the main-only GitHub Pages environment

Validation

• 2,222 non-GPU/non-network tests passed; 10 skipped, 22 deselected; 83.95% branch coverage
• release-state, generated PyPI README, Ruff, format, mypy, strict MkDocs, generated artifacts, text integrity, and Markdown links passed
• public miniverl 0.9.0 clean install and doctor passed
• recovery Pages workflow 31682785478 passed and the public root reports Stable 0.9.0
• frozen benchmark paths have no diff; calculator SHA-256 remains 53fc1d4d5b7adee09618d77ad62d4086ba56b78569832d6fc7c3bcd5c2695bbc