V1 launch readiness update

SpendLens now has aligned benchmark/report flows, safer session handling, stronger production copy, and a cleaner launch posture across the public site and admin workspace.

What changed

This pass focused on making SpendLens safer to launch without changing its core research direction.

The main work tightened configuration handling, aligned benchmark/report behavior, and removed remaining prototype-era mismatches in copy, metadata, and fallback states.

Cleaner environment-variable handling for public and server-only keys
Benchmark access tied to the active anonymous session in the browser
Privacy, footer, and metadata copy aligned with the real product behavior
Launch-ready deployment notes and go-live checklist

Why this matters

Launch risk usually comes from small mismatches: internal wording in public paths, loose env assumptions, or benchmark/report features that behave differently across screens.

SpendLens is now better positioned for a controlled first release with clearer operational setup and fewer avoidable surprises.