Validate Genblaze workflow

[nexicturbo]

What changed

• pin the published Genblaze 0.3 package line that actually resolves from PyPI
• validate the web build and rendered control room in CI
• run the complete three-attempt Genblaze fixture workflow in CI and verify its manifest lineage
• document the honest fixture/B2 behavior and ignore local runtime artifacts

Why

The repository referenced unreleased 0.6.x package versions, so a judge following the setup instructions could not install or run the Python workflow. The new CI gate proves that both the public web app and the Genblaze pipeline remain reproducible.

Validation

• npm test
• Python 3.12 install from requirements.txt
• fixture workflow passes in three attempts with a verified canonical manifest and parent-linked run chain