Persist upstream Radar review artifacts

[yvette-carlisle]

Summary

• Refreshed the deterministic openai/codex upstream review queue.
• Added GitHub change bundles, upstream reviews, and upstream impact records for PRs 26548, 26674, 25936, and 26490.
• Added social_candidate/v1 handoffs for PRs 26548, 25936, and 26490 only; no social_post/v1 artifacts were written and nothing was published to X.

Reviewed subjects

• [2 of 2] Finish moving goal runtime to extension openai/codex#26548: goal runtime moved to extension-backed GoalService path; social candidate is defer/operator-impact.
• protocol: remove submission-side serde from Op openai/codex#26674: submission-side Op serde removed; impact record only.
• [codex] Remove legacy remote plugin startup sync openai/codex#25936: legacy remote plugin startup sync removed; social candidate is publish/operator-impact.
• [codex] Use standalone tools for Responses Lite openai/codex#26490: Responses Lite routes web search and image generation through standalone executors; social candidate is publish/practical-explainer.

Validation

• cargo run -p decodex --bin decodex -- radar bundle validate artifacts/github/bundles/openai-codex-pr-26548.json artifacts/github/bundles/openai-codex-pr-26674.json artifacts/github/bundles/openai-codex-pr-25936.json artifacts/github/bundles/openai-codex-pr-26490.json
• cargo run -p decodex --bin decodex -- radar validate artifacts/github/review-queue artifacts/github/bundles artifacts/github/reviews artifacts/github/impact artifacts/github/social-candidates
• cargo make check-site-content
• cargo make fmt
• cargo make lint-fix
• cargo make test

Note: this repository currently has no codex or codex-automation labels to apply.