fix(health-score): build the BP pillar from one shared input builder

The Personal Health Score was assembled differently by its two callers. The
analytics route (the Insights card) graded the BP pillar off one window and
passed the prior-week values for the week-over-week delta; the dashboard
snapshot (the hero ring) graded it off a different window and omitted the
prior-week values, so the ring's delta zeroed BP out and the pillar's presence
gate could flip. The same user could see two different scores and two
different bands on two surfaces.

Extract `buildHealthScoreBpInputs` — one pure builder that turns the current
and prior-week in-target envelopes into the BP-pillar inputs (the 90-day rate
with an all-time fallback, the graded clinical-proximity score, and the
prior-week counterparts for the delta). Both callers now run the same two
in-target probes and feed the pillar through this builder, so the window
choice, the fallback, the graded-score wiring and the delta inputs are
identical by construction and can never drift between the surfaces again.

The dashboard ring now runs the prior-week probe it previously skipped, so its
week-over-week delta reflects BP movement to match the Insights card.

src/app/api/analytics/route.ts

@@ -12,8 +12,12 @@ import { reconstructSleepNights } from "@/lib/analytics/sleep-night";
 import { loadUserSourcePriority } from "@/lib/rollups/measurement-read";
 import { ensureUserRollupsFresh } from "@/lib/rollups/measurement-rollups";
 import { probeRollupCoverage } from "@/lib/rollups/measurement-coverage";
-import { computeBpInTargetFastPath } from "@/lib/analytics/bp-in-target-fast-path";
+import {
+  computeBpInTargetFastPath,
+  type BpInTargetEnvelope,
+} from "@/lib/analytics/bp-in-target-fast-path";
 import { computeUserHealthScoreFastPath } from "@/lib/analytics/health-score-fast-path";
+import { buildHealthScoreBpInputs } from "@/lib/analytics/health-score-inputs";
 import { computeCorrelationHypothesesFastPath } from "@/lib/analytics/correlations-fast-path";
 
 export const dynamic = "force-dynamic";
@@ -242,8 +246,6 @@ async function buildAnalyticsResponse(user: AuthedUser) {
   let bpInTargetPct: number | null = null;
   let bpInTargetPct7d: number | null = null;
   let bpInTargetPct30d: number | null = null;
-  // v1.17 W1d — the canonical 90-day window for the headline / score / coach.
-  let bpInTargetPct90d: number | null = null;
   let bpInTargetPctAllTime: number | null = null;
   /**
    * v1.4.22 W5 reconcile (Code-H2) — period-aligned prior-window
@@ -255,25 +257,13 @@ async function buildAnalyticsResponse(user: AuthedUser) {
    */
   let bpInTargetPctPriorMonth: number | null = null;
   let bpInTargetPctPriorYear: number | null = null;
-  /**
-   * v1.4.38 — prior-week BP-in-target pct so the Health-Score
-   * week-over-week delta reflects BP movement. Pre-v1.4.38 the
-   * Health-Score helper pinned both windows to the same value, so the
-   * BP pillar always zeroed out of the delta. Computed by running a
-   * second `computeBpInTargetFastPath` against `now - 7d` and reading
-   * the resulting `last30Days.pct`.
-   */
-  let bpInTargetPctPriorWeek: number | null = null;
-  // v1.17 W1d — prior-week 90-day BP pct. Feeds the Health-Score delta so
-  // its BP pillar compares the same 90-day window on both ends, identical
-  // to the headline scope. (Pre-v1.17 the score read all-time; W1d
-  // unifies headline + score + coach on 90 days.)
-  let windowsPriorWeekForScore: number | null = null;
-  // v1.15.12 A1 — graded clinical-proximity BP score (recency-weighted
-  // representative reading) for the Health-Score BP pillar value, plus
-  // the prior-week run for the week-over-week delta.
-  let bpGradedScore: number | null = null;
-  let bpGradedScorePriorWeek: number | null = null;
+  // v1.17 W1b — hold the current + prior-week BP envelopes so the shared
+  // Health-Score input builder grades the pillar off the identical shape the
+  // dashboard snapshot uses (one builder, no per-surface assembly drift).
+  // The graded score + prior-week BP figures the score consumes are read off
+  // these envelopes inside `buildHealthScoreBpInputs`.
+  let bpEnvelope: BpInTargetEnvelope | null = null;
+  let bpEnvelopePriorWeek: BpInTargetEnvelope | null = null;
   const bpTargets = getBpTargets(user.dateOfBirth);
   if (bpTargets) {
     const now = new Date();
@@ -318,24 +308,17 @@ async function buildAnalyticsResponse(user: AuthedUser) {
         userTz,
       }),
     ]);
+    bpEnvelope = windows;
+    bpEnvelopePriorWeek = windowsPriorWeek;
     // v1.17 W1d — the BD-Zielbereich headline standardises on the
     // trailing-90-day window (labelled "· 90 T" in the tile). All-time
     // remains carried below for the BP detail page's long view only.
     bpInTargetPct = windows.last90Days?.pct ?? null;
     bpInTargetPct7d = windows.last7Days?.pct ?? null;
     bpInTargetPct30d = windows.last30Days?.pct ?? null;
-    bpInTargetPct90d = windows.last90Days?.pct ?? null;
     bpInTargetPctAllTime = windows.allTime?.pct ?? null;
     bpInTargetPctPriorMonth = windows.priorMonth?.pct ?? null;
     bpInTargetPctPriorYear = windows.priorYear?.pct ?? null;
-    bpInTargetPctPriorWeek = windowsPriorWeek.last90Days?.pct ?? null;
-    bpGradedScore = windows.gradedScore;
-    bpGradedScorePriorWeek = windowsPriorWeek.gradedScore;
-    // v1.17 W1d — the Health-Score BP pillar reads the same 90-day window
-    // as the headline (see `bpInTargetPctForScore` below). Capture the
-    // prior-week run's 90-day pct so the week-over-week delta compares the
-    // same window on both ends.
-    windowsPriorWeekForScore = windowsPriorWeek.last90Days?.pct ?? null;
   }
 
   // Per-context glucose summaries (canonical mg/dL).
@@ -393,41 +376,17 @@ async function buildAnalyticsResponse(user: AuthedUser) {
   // 2-column projection from `measurements` for the ingest-path
   // pills. Falls back to the legacy 37-day raw read on partial /
   // missing coverage. Path annotate sits on `meta.healthScore.path`.
-  // The Health-Score BP pillar reads the **all-time** in-target rate, not
-  // the BD-Zielbereich tile headline (which v1.4.x deliberately scopes to
-  // the trailing 30 days). Feeding the tile's `bpInTargetPct` (last-30d)
-  // here regressed the pillar to null for any account with BP history but
-  // no readings inside the trailing month — the score then dropped the
-  // 0.30-weight BP pillar entirely and rendered "no rating" despite the
-  // user having BP data. `health-score.ts` documents the field as the
-  // all-time rate, so route the all-time window through; fall back to the
-  // 30-day window only when the all-time window is itself null (it never
-  // is when 30-day has data), so a brand-new account is unaffected.
-  // v1.17 W1d — the Health-Score BP pillar reads the SAME 90-day window as
-  // the BD-Zielbereich tile headline, so the dashboard ring and the
-  // insights card grade the BP pillar off one number. Fall back to the
-  // all-time rate only when the 90-day window is itself null so a
-  // sparse-but-historical account still surfaces a BP pillar.
-  const bpInTargetPctForScore = bpInTargetPct90d ?? bpInTargetPctAllTime;
-  const bpInTargetPctPriorWeekForScore =
-    windowsPriorWeekForScore ?? bpInTargetPctPriorWeek;
+  //
+  // v1.17 W1b — the BP-pillar inputs come from the ONE shared
+  // `buildHealthScoreBpInputs` builder the dashboard snapshot also uses, so
+  // the ring and the insights card grade the pillar off identical inputs
+  // (same 90-day window via W1d, same all-time fallback, same graded score,
+  // same prior-week delta values). The hand-rolled per-surface assembly that
+  // let the two diverge is gone.
+  const bpInputs = buildHealthScoreBpInputs(bpEnvelope, bpEnvelopePriorWeek);
   const healthScore = await computeUserHealthScoreFastPath({
     userId: user.id,
-    bpInTargetPct: bpInTargetPctForScore,
-    // v1.4.38 — feed the prior-week BP pct into the Health-Score
-    // helper's previous-window snapshot so the week-over-week delta
-    // reflects BP movement instead of zeroing out of the BP pillar.
-    // Computed alongside the current windows via a second
-    // `computeBpInTargetFastPath` run anchored at `now - 7d`. Uses the
-    // same all-time window as the current snapshot so the delta is
-    // apples-to-apples.
-    bpInTargetPctPriorWeek: bpInTargetPctPriorWeekForScore,
-    // v1.15.12 A1 — graded clinical-proximity BP score drives the pillar
-    // VALUE; the binary in-target rate above only gates presence and is
-    // surfaced as a secondary stat. Closes the "borderline-stage-1 reads
-    // 16/100" trust bug.
-    bpGradedScore,
-    bpGradedScorePriorWeek,
+    ...bpInputs,
     heightCm: user.heightCm ?? null,
     now: new Date(),
     coverage,