Persist upstream Radar review artifacts

[yvette-carlisle]

Summary

• refreshed the deterministic openai/codex upstream review queue
• added GitHub change bundles for PRs 25177, 22879, and 27184
• added source-backed upstream_review/v1 and upstream_impact/v1 artifacts for PRs 25177, 22879, and 27184
• added social_candidate/v1 handoffs for public Publisher opportunities in PRs 22879 and 27184

Validation

• cargo run -q -p decodex --bin decodex -- radar bundle validate artifacts/github/bundles/openai-codex-pr-25177.json artifacts/github/bundles/openai-codex-pr-22879.json artifacts/github/bundles/openai-codex-pr-27184.json
• cargo run -q -p decodex --bin decodex -- radar validate artifacts/github/review-queue artifacts/github/reviews artifacts/github/impact artifacts/github/social-candidates artifacts/github/bundles

Notes

• No social_post/v1 records were written and nothing was published to X.
• Repository labels codex and codex-automation were not present, so no labels were applied.