[sarthakagrawal927]

This change records content-minimized delayed-transfer receipts only when an authenticated review has a prior question-level due schedule. The server validates the linked intervention and snapshots that question schedule before the FSRS update; receipt insertion remains best-effort after the review save. Concept-only due metadata does not qualify a receipt, and the normal independent concept FSRS review path is unchanged. Detached generic activity writes cannot create receipts.

Today uses recorded failed or unknown outcomes only when the concept is currently due; pending interventions remain informational. Normal concept-due review actions continue even when no question-backed receipt can be recorded. Human transfer outcomes and the original outcome study remain separate future work.

Validation: 14 final focused handler tests pass; targeted Biome passes; exact-head CI passed on 49f2121 (run 40289723144). Full-range CodeVetter Claude review passed with limits on 64f24b6; it found concept-provenance acceptance in the shared receipt validator, fixed in 49f2121. Its suggestion to gate normal retry UI was declined because concept-due reviews remain supported without a receipt. Root reviewed the final validator delta with no findings (private evidence: execution-fixes-2026-10-26/swe-final-validator-root-review.json).

Merged as 6f87ca5. Production Pages deployment run 40290068202 passed tests, build, deployment, and production smoke checks with migrations disabled; deployment: https://2d7dbad6.swe-interview-prep.pages.dev. The previous Pages deployment remains available from the Cloudflare Pages deployment history for rollback. No owner data was used. The outcome study remains deferred and separate from this measurement setup.