docs: record staging deployment evidence

[gcharang]

Summary

• record PR fix: preserve deployment failure evidence #26 and its merge commit in the rollout baseline
• record passing post-merge CI and Version runs
• distinguish the still-blocked staging upload from the now-successful failure-evidence artifact upload
• preserve the exact external blocker: the staging GitHub environment has no CLOUDFLARE_API_TOKEN

Verification

• git diff --check
• claims verified against PR fix: preserve deployment failure evidence #26, runs 30886405878 / 30886405689 / 30886405702, and the downloaded staging evidence artifact

Release metadata

No changeset is required; this is documentation-only.

AI disclosure

Updated with Codex from verified GitHub workflow and artifact evidence.