perf(analytics): probe-gated healthScore on rollup-fast-path

The Personal Health Score builder used to read 37 days of raw weight
rows from the measurements table on every dashboard mount. When DAY
rollup coverage exists for WEIGHT, the new helper derives the weight
series from per-day MEAN values in measurement_rollups and only
issues a narrow 2-column projection against measurements for the
source-attribution pill (the rollup table does not carry the source
enum). Partial-coverage and brand-new accounts keep the legacy 37-day
raw read so the score stays correct on first cold-mount.

Mood, medications, and intake events still read live regardless of
coverage — none has a rollup equivalent today. A path:"rollup"|
"live" annotate on meta.healthScore.path makes the branch selection
provable in prod logs, matching the bp_in_target and summaries-slice
patterns.

Body relocated from route.ts to lib/analytics/health-score-fast-path.ts
so the dispatcher can be unit-tested against mocked Prisma without a
container. Unit test pins both branches (probe → rollup, probe →
live), the empty-component-set early-out, and the implicit-probe
shortcut for callers that omit the coverage map.

src/app/api/analytics/route.ts

@@ -8,14 +8,6 @@ import { summarize, type DataPoint } from "@/lib/analytics/trends";
 import { computeSummariesSlice } from "@/lib/analytics/summaries-slice";
 import { getBpTargets } from "@/lib/analytics/bp-targets";
 import { userDayKey, DEFAULT_TIMEZONE } from "@/lib/tz/resolver";
-import { calculateCompliance } from "@/lib/analytics/compliance";
-import {
-  computeHealthScore,
-  defaultWeightTargetFromHeight,
-  type ContributingSource,
-  type HealthScoreInput,
-  type HealthScoreResult,
-} from "@/lib/analytics/health-score";
 import {
   correlateBpCompliance,
   correlateMoodPulse,
@@ -32,6 +24,7 @@ import type { SourcePriorityMetricKey } from "@/lib/validations/source-priority"
 import { ensureUserRollupsFresh } from "@/lib/measurements/rollups";
 import { probeRollupCoverage } from "@/lib/measurements/rollup-coverage";
 import { computeBpInTargetFastPath } from "@/lib/analytics/bp-in-target-fast-path";
+import { computeUserHealthScoreFastPath } from "@/lib/analytics/health-score-fast-path";
 import {
   isCumulativeDaySumType,
   pickCumulativeDaySum,
@@ -407,21 +400,20 @@ async function buildAnalyticsResponse(user: AuthedUser) {
   // composite of BP-in-target % + weight-trend alignment + mood
   // stability + medication compliance. The "vs last week" delta
   // re-runs the same compute against a 7-day-shifted snapshot.
-  const healthScore = await computeUserHealthScore(user.id, {
+  //
+  // v1.4.37 W2 — probe-gated helper. The weight pillar derives from
+  // DAY-bucket means on `measurement_rollups` when the user has full
+  // coverage; the source-attribution accordion still pulls a narrow
+  // 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`.
+  const healthScore = await computeUserHealthScoreFastPath({
+    userId: user.id,
     bpInTargetPct,
     heightCm: user.heightCm ?? null,
+    now: new Date(),
+    coverage,
   });
-  if (healthScore) {
-    annotate({
-      meta: {
-        healthScore: {
-          score: healthScore.score,
-          band: healthScore.band,
-          delta: healthScore.delta,
-        },
-      },
-    });
-  }
 
   return {
     summaries: results,
@@ -821,286 +813,8 @@ function isoWeekdayInTz(d: Date, timeZone: string): number {
 }
 
 
-/**
- * v1.4.25 W8e — collapse the persisted `MeasurementSource` enum onto
- * the camelCase token set the health-score analytics layer consumes.
- *
- * - `MANUAL` and `IMPORT` (CSV import — still user-supplied data) both
- *   surface as `"manual"`.
- * - `WITHINGS` and `APPLE_HEALTH` ride one-to-one.
- *
- * Returns `null` for source values that don't fall into the three
- * exposed buckets — defence-in-depth in case the enum grows before the
- * client is taught about it.
- */
-function mapMeasurementSourceToLabel(
-  source: MeasurementSource,
-): ContributingSource | null {
-  switch (source) {
-    case "MANUAL":
-    case "IMPORT":
-      return "manual";
-    case "WITHINGS":
-      return "withings";
-    case "APPLE_HEALTH":
-      return "appleHealth";
-    default:
-      return null;
-  }
-}
-
-/**
- * v1.4.25 W8e — deduplicate the contributing-source list for a single
- * component. Returns the empty array when nothing in the input maps
- * onto a known label so downstream `resolveSourceLabel` falls through
- * to `none` (matches the empty-state branch).
- */
-function uniqueComponentSources(
-  rows: ReadonlyArray<MeasurementSource>,
-): ReadonlyArray<ContributingSource> {
-  const seen = new Set<ContributingSource>();
-  for (const src of rows) {
-    const label = mapMeasurementSourceToLabel(src);
-    if (label) seen.add(label);
-  }
-  return Array.from(seen);
-}
-
-/**
- * Build the Health Score input from the user's last-30-day weight,
- * mood, and medication-compliance data, plus the already-computed
- * `bpInTargetPct` headline. Re-runs the same compute against a
- * 7-day-shifted window to populate the "vs last week" delta.
- *
- * Returns null when the score wouldn't carry any signal (every
- * component nullable + no medications). The route surfaces the
- * `null` to the UI so the hero panel hides cleanly.
- */
-async function computeUserHealthScore(
-  userId: string,
-  input: { bpInTargetPct: number | null; heightCm: number | null },
-): Promise<HealthScoreResult | null> {
-  const DAY_MS = 24 * 60 * 60 * 1000;
-  const now = new Date();
-  const since30d = new Date(now.getTime() - 30 * DAY_MS);
-  // Prior week's snapshot — shift everything 7 days into the past so
-  // both windows close at the same wall-clock-of-day boundary.
-  const prevSince30d = new Date(now.getTime() - 37 * DAY_MS);
-  const prevUntil = new Date(now.getTime() - 7 * DAY_MS);
-
-  // v1.4.25 W8e — read the `source` column alongside the value so the
-  // health-score provenance accordion knows which ingest path drove
-  // each component. The weight + BP reads already paid the row cost;
-  // adding the column to the SELECT is free in Postgres terms (no extra
-  // round-trip, no extra plan node) and the alternative — a second
-  // aggregate just for the source pill — would burn another findMany.
-  const [weightRows, bpSysRowsForSource, moodRows, medications] =
-    await Promise.all([
-      prisma.measurement.findMany({
-        where: {
-          userId,
-          type: "WEIGHT",
-          measuredAt: { gte: prevSince30d, lte: now },
-        },
-        select: { value: true, measuredAt: true, source: true },
-        orderBy: { measuredAt: "asc" },
-      }),
-      // BP source attribution rides on the systolic-readings row set —
-      // diastolic rows always carry the same `source` because both
-      // halves of a pair are persisted in the same write. Pull only the
-      // trailing 30 days to keep the call bounded for power users.
-      prisma.measurement.findMany({
-        where: {
-          userId,
-          type: "BLOOD_PRESSURE_SYS",
-          measuredAt: { gte: since30d, lte: now },
-        },
-        select: { measuredAt: true, source: true },
-        orderBy: { measuredAt: "asc" },
-      }),
-      prisma.moodEntry.findMany({
-        where: {
-          userId,
-          moodLoggedAt: { gte: prevSince30d, lte: now },
-        },
-        select: { score: true, moodLoggedAt: true },
-        orderBy: { moodLoggedAt: "asc" },
-      }),
-      prisma.medication.findMany({
-        where: { userId, active: true },
-        select: {
-          id: true,
-          createdAt: true,
-          schedules: {
-            select: {
-              windowStart: true,
-              windowEnd: true,
-            },
-          },
-        },
-      }),
-    ]);
-
-  // Compliance30 per active medication, then again for the prior-week
-  // snapshot. The compliance helper anchors on `Date.now()` internally;
-  // for the previous-week snapshot we reuse the same helper but pass a
-  // shifted "createdAt" floor so the window mathematically reflects the
-  // [-37d, -7d] period — equivalent to running the helper a week ago.
-  let medicationCompliance30: number[] = [];
-  let medicationCompliance30Previous: number[] = [];
-  if (medications.length > 0) {
-    const medIds = medications.map((m) => m.id);
-    const intakeEvents = await prisma.medicationIntakeEvent.findMany({
-      where: {
-        userId,
-        medicationId: { in: medIds },
-        scheduledFor: { gte: prevSince30d, lte: now },
-      },
-      select: {
-        medicationId: true,
-        scheduledFor: true,
-        takenAt: true,
-        skipped: true,
-      },
-    });
-    const eventsByMed = new Map<string, typeof intakeEvents>();
-    for (const ev of intakeEvents) {
-      const list = eventsByMed.get(ev.medicationId);
-      if (list) list.push(ev);
-      else eventsByMed.set(ev.medicationId, [ev]);
-    }
-    medicationCompliance30 = medications.map((med) => {
-      const events = eventsByMed.get(med.id) ?? [];
-      return calculateCompliance(events, med.schedules, 30, med.createdAt).rate;
-    });
-    medicationCompliance30Previous = medications.map((med) => {
-      const events = (eventsByMed.get(med.id) ?? []).filter(
-        (e) => e.scheduledFor <= prevUntil,
-      );
-      // Compute compliance against the prior-week-aligned window by
-      // remapping the helper's "now": shift each event's scheduledFor
-      // and takenAt forward by 7 days so the helper's internal `now`
-      // anchor still captures the same logical 30 days.
-      const shifted = events.map((e) => ({
-        scheduledFor: new Date(e.scheduledFor.getTime() + 7 * DAY_MS),
-        takenAt: e.takenAt ? new Date(e.takenAt.getTime() + 7 * DAY_MS) : null,
-        skipped: e.skipped,
-      }));
-      return calculateCompliance(shifted, med.schedules, 30, med.createdAt)
-        .rate;
-    });
-  }
-
-  const fallbackTarget = defaultWeightTargetFromHeight(input.heightCm);
-
-  const weightSeriesLast30d = weightRows
-    .filter((r) => r.measuredAt >= since30d)
-    .map((r) => ({ date: r.measuredAt.toISOString(), kg: r.value }));
-  const weightSeriesPrev30d = weightRows
-    .filter((r) => r.measuredAt >= prevSince30d && r.measuredAt <= prevUntil)
-    .map((r) => ({ date: r.measuredAt.toISOString(), kg: r.value }));
-
-  const moodSeriesLast30d = moodRows
-    .filter((r) => r.moodLoggedAt >= since30d)
-    .map((r) => ({
-      date: r.moodLoggedAt.toISOString(),
-      score: r.score,
-    }));
-  const moodSeriesPrev30d = moodRows
-    .filter(
-      (r) => r.moodLoggedAt >= prevSince30d && r.moodLoggedAt <= prevUntil,
-    )
-    .map((r) => ({
-      date: r.moodLoggedAt.toISOString(),
-      score: r.score,
-    }));
-
-  // Skip any input shape where literally nothing is computable — the
-  // hero panel hides instead of painting a misleading "0".
-  if (
-    input.bpInTargetPct === null &&
-    weightSeriesLast30d.length === 0 &&
-    moodSeriesLast30d.length === 0 &&
-    medicationCompliance30.length === 0
-  ) {
-    // Tag-only annotation so admin observability can see the empty path.
-    annotate({
-      meta: {
-        healthScore: { score: null, reason: "no_components_available" },
-      },
-    });
-    return null;
-  }
-
-  // v1.4.25 W8e — build per-component source attribution from the rows
-  // we already hold in memory. `mapMeasurementSourceToLabel` collapses
-  // the persisted `MeasurementSource` enum onto the camelCase token list
-  // the analytics helper consumes; `IMPORT` rides under `manual`
-  // because the v1.4.20 CSV importer ingests user-supplied data — it's
-  // not a wearable stream.
-  const windowEndAt = now.toISOString();
-
-  const weightSourcesIn30d = uniqueComponentSources(
-    weightRows
-      .filter((r) => r.measuredAt >= since30d)
-      .map((r) => r.source),
-  );
-  const latestWeightInWindow = weightRows
-    .filter((r) => r.measuredAt >= since30d)
-    .at(-1);
-
-  const bpSourceTokens = uniqueComponentSources(
-    bpSysRowsForSource.map((r) => r.source),
-  );
-  const latestBpInWindow = bpSysRowsForSource.at(-1);
-
-  // Mood doesn't yet have a non-manual ingest (v1.5 will introduce
-  // Apple Health mood) so the source list is always `["manual"]` when
-  // there are entries in window. Keep the lookup explicit so the
-  // v1.5 ingest path slot just drops in.
-  const moodSourceTokens = moodSeriesLast30d.length > 0
-    ? (["manual"] as const)
-    : [];
-  const latestMoodInWindow = moodRows
-    .filter((r) => r.moodLoggedAt >= since30d)
-    .at(-1);
-
-  // Medication compliance always derives from logged intake events —
-  // user-driven manual logging today.
-  const complianceSourceTokens = medicationCompliance30.length > 0
-    ? (["manual"] as const)
-    : [];
-
-  const current: HealthScoreInput = {
-    bpInTargetRate: input.bpInTargetPct,
-    weightSeriesLast30d,
-    weightTargetKg: fallbackTarget,
-    moodEntriesLast30d: moodSeriesLast30d,
-    medicationCompliance30,
-    attribution: {
-      bpSources: bpSourceTokens,
-      asOfBp: latestBpInWindow?.measuredAt.toISOString() ?? null,
-      weightSources: weightSourcesIn30d,
-      asOfWeight: latestWeightInWindow?.measuredAt.toISOString() ?? null,
-      moodSources: moodSourceTokens,
-      asOfMood: latestMoodInWindow?.moodLoggedAt.toISOString() ?? null,
-      complianceSources: complianceSourceTokens,
-      asOfCompliance: complianceSourceTokens.length > 0 ? windowEndAt : null,
-      windowEndAt,
-    },
-  };
-  // The all-time `bpInTargetPct` is a slow-moving aggregate and would
-  // need a full historical re-pair to "rewind" by a week. We pass the
-  // same value to the previous snapshot so the delta primarily
-  // reflects week-over-week changes in the weight / mood / compliance
-  // pillars — the components that actually move on a weekly cadence.
-  const previous: HealthScoreInput = {
-    bpInTargetRate: input.bpInTargetPct,
-    weightSeriesLast30d: weightSeriesPrev30d,
-    weightTargetKg: fallbackTarget,
-    moodEntriesLast30d: moodSeriesPrev30d,
-    medicationCompliance30: medicationCompliance30Previous,
-  };
-
-  return computeHealthScore(current, previous);
-}
+// v1.4.37 W2 — `mapMeasurementSourceToLabel`, `uniqueComponentSources`,
+// and the inline `computeUserHealthScore` body relocated to
+// `src/lib/analytics/health-score-fast-path.ts` so the probe-gated
+// rollup / live dispatcher can be unit-tested independently of the
+// route. The route now delegates through `computeUserHealthScoreFastPath`.