Each recommendation now carries a 3-field `rationale` object that
powers the upcoming Oura-style "Contributors" expand-card:
- dataWindow: which time window the rec is based on (matches the
metricSource.timeRange enum so the UI mini-chart can pin to it)
- comparedTo: what the user's data is being compared against
(the user's own baseline or a guideline ceiling)
- deviation: size + direction of the deviation that triggered
the rec
Empty `comparedTo` or `deviation` is rejected so the model cannot
emit a placeholder rationale card. Optional `referenceId` rides
along for defence-in-depth; the rec-level referenceId stays the
canonical citation source.
`findRecommendationsMissingRationale()` lets the route detect
legacy (pre-B5c) cached payloads so the UI can show a "regenerate
for new explainability features" CTA. User-initiated regeneration
stays the trigger; nothing auto-runs.
10 new tests in `rationale-schema.test.ts` pin the contract:
- rationale required on every rec
- comparedTo / deviation reject empty strings
- dataWindow rejects unknown enum values
- legacy payload detector returns missing rec ids only
- mixed payloads flag only the legacy entries
Existing test fixtures in `generate-insight.test.ts`,
`reference-id-schema.test.ts`, `citation-enforcement.test.ts`,
and `citation-coverage-logging.test.ts` updated to include
rationale on every well-formed rec — typecheck-clean.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Recommendations now carry an optional `referenceId` that the parser
checks against the curated bundle from the previous commit. A
fabricated id ("invented-guideline-2099") fails parse so the model
cannot synthesise a citation for a guideline that does not exist —
defence in depth on top of the prompt-side instruction.
Optional in v1.4.16 so existing payloads still validate; v1.4.16
phase B5c ratchets it to required when severity >= "important". Also
bumps PROMPT_VERSION to 4.16.0 for the system-prompt update landing
in the next commit.
8 unit tests pin the accept-known / reject-fabricated / mixed-payload
behaviour and the round-trip preservation of referenceId through the
strict response schema.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
