GreenGate: the agent proposes, the phone decides — building an Auth0 CIBA + Gemini audit for embodied carbon

This is a submission for Weekend Challenge: Earth Day Edition Construction is responsible for roughly 37% of global energy-related CO₂ emissions (UNEP Global Status Report for Buildings). Most of that footprint is decided at the Bill of Materials stage — before anything gets poured, welded, or framed. Audit a BOM against peer-reviewed emission factors and you can cut 10-30% off a project before ground is broken. The math is a spreadsheet. The consequence of changing a material — the structural c