fix(medications): tally the cadence chips from the compliance ledger

`/api/medications/[id]/cadence` computed its adherence chip from a
private copy of the compliance ledger that ignored pause eras, courses
and auto-missed doses, and read only the chart's window of intakes. A
medication paused for a week read 77 % there and 100 % on the detail
page. The chips now tally `trailingComplianceLedger`, the ledger the
compliance payload builds, over the same window, with the medication's
pauses and courses; the copy is removed and a guard freezes the set of
files that build dose rows.

src/__tests__/dose-ledger-single-source-guard.test.ts

@@ -0,0 +1,55 @@
+/**
+ * Structural guard: medication compliance is tallied from one ledger.
+ *
+ * The cadence chips carried a private copy of the ledger build that
+ * `lib/analytics/compliance/ledger.ts` owns, minus the pause eras and the
+ * courses, so `/api/medications/[id]/cadence` could report 77 % for a month
+ * the detail page called 100 %. The chips now tally the shared ledger.
+ *
+ * `reconstructDoseHistory` is the step that turns minted bands and intakes
+ * into dose rows. The set of files that call it is frozen: the ledger, the
+ * cadence timeline (the chart and the streaks) and the dose-history view. A
+ * new caller is a new ledger and has to be added here, next to a reason.
+ * Comments are stripped first; the count floor proves the matcher reads.
+ */
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+import { describe, expect, it } from "vitest";
+
+import { walkSourceFiles } from "./helpers/source-files";
+
+const SRC = join(process.cwd(), "src");
+
+const CALLERS: Record<string, string> = {
+  "lib/analytics/compliance/ledger.ts":
+    "The compliance ledger every rate and the chips tally.",
+  "lib/medications/scheduling/cadence.ts":
+    "The cadence timeline the chart draws and the streaks walk.",
+  "app/api/medications/[id]/dose-history/route.ts":
+    "The dose-history view, row by row over the same bands.",
+};
+
+const CALL = /\breconstructDoseHistory\s*\(/;
+
+function stripComments(text: string): string {
+  return text.replace(/\/\*[\s\S]*?\*\//g, "").replace(/^\s*\/\/.*$/gm, "");
+}
+
+describe("one compliance ledger", () => {
+  it("the dose rows are built only where this file says", () => {
+    const callers = walkSourceFiles(SRC, { floor: 3000 })
+      .filter(
+        (file) =>
+          !file.startsWith("generated/") &&
+          !file.includes("__tests__/") &&
+          !/\.test\.tsx?$/.test(file) &&
+          file !== "lib/medications/scheduling/dose-history.ts",
+      )
+      .filter((file) =>
+        CALL.test(stripComments(readFileSync(join(SRC, file), "utf8"))),
+      )
+      .sort();
+    expect(callers.length).toBeGreaterThanOrEqual(3);
+    expect(callers).toEqual(Object.keys(CALLERS).sort());
+  });
+});

src/app/api/medications/[id]/cadence/route.ts

@@ -24,10 +24,12 @@ import { apiError, apiSuccess, returnAllZodIssues } from "@/lib/api-response";
 import {
   buildCadenceTimeline,
   computeNextDose,
-  type CadenceEngineContext,
 } from "@/lib/medications/scheduling/cadence";
 import { complianceChips } from "@/lib/medications/scheduling/compliance";
 import {
+  buildComplianceMedicationContext,
+  COMPLIANCE_LEDGER_WINDOW_DAYS,
+  COURSES_COMPLIANCE_SELECT,
   lastNonSkippedTakenAt,
   SCHEDULE_COMPLIANCE_SELECT,
 } from "@/lib/analytics/compliance";
@@ -58,6 +60,11 @@ export const GET = apiHandler(
         schedules: { select: SCHEDULE_COMPLIANCE_SELECT },
         // v1.16.3 — archived schedule eras for era-aware chips/tallies.
         scheduleRevisions: { orderBy: { validFrom: "asc" } },
+        // The pause eras and courses, so the chips tally the ledger the
+        // detail page's rate reads: a paused day or a gap between two
+        // courses expects nothing.
+        pauseEras: { select: { pausedAt: true, resumedAt: true } },
+        courses: COURSES_COMPLIANCE_SELECT,
       },
     });
     if (!med) {
@@ -75,11 +82,13 @@ export const GET = apiHandler(
     const windowDays = parsed.data.days ?? 30;
     const asOf = new Date();
 
-    // Pull intake events covering the window + a small buffer so a dose
-    // logged at the edge can still pair with its slot.
-    const bufferMs = 24 * 60 * 60 * 1000;
+    // The events the compliance ledger reads (its full trailing year plus a
+    // day): the chips tally the same rows as the detail page, and a rolling
+    // cadence re-anchors on the latest intake even when it predates the
+    // chart's window.
     const from = new Date(
-      asOf.getTime() - windowDays * 24 * 60 * 60 * 1000 - bufferMs,
+      asOf.getTime() -
+        (COMPLIANCE_LEDGER_WINDOW_DAYS + 1) * 24 * 60 * 60 * 1000,
     );
     const events = await prisma.medicationIntakeEvent.findMany({
       where: {
@@ -93,6 +102,8 @@ export const GET = apiHandler(
         scheduledFor: true,
         takenAt: true,
         skipped: true,
+        // A dose the auto-miss job closed counts as missed, as in the rate.
+        autoMissed: true,
         // v1.15.20 — pinned takes bind by anchor in the chip tally so the
         // chips agree with the % + the history on a "zugeordnet" dose.
         attributionSource: true,
@@ -121,16 +132,11 @@ export const GET = apiHandler(
     // legacy weekday walker (e.g. `FREQ=WEEKLY;BYDAY=MO` expands daily,
     // PRN counts as a real cadence) and disagrees with the dashboard.
     // Mirrors `analytics/compliance.ts`'s context construction.
-    const lastIntakeAt = lastNonSkippedTakenAt(events);
-    const engineCtx: CadenceEngineContext = {
-      startsOn: med.startsOn,
-      endsOn: med.endsOn,
-      oneShot: med.oneShot,
-      createdAt: med.createdAt,
-      lastIntakeAt,
-      timeZone: userTz,
-      scheduleRevisions: med.scheduleRevisions,
-    };
+    const engineCtx = buildComplianceMedicationContext(
+      med,
+      lastNonSkippedTakenAt(events),
+      userTz,
+    );
 
     // v1.39.1 (#1033) — intake tracking off: no chip, no next dose.
     const liveSchedules = dueSchedules(med);
@@ -146,11 +152,10 @@ export const GET = apiHandler(
     const chips = complianceChips(
       liveSchedules,
       events,
+      engineCtx,
       asOf,
       windowDays,
       anchor,
-      userTz,
-      engineCtx,
     );
     const next = computeNextDose(
       liveSchedules,

src/lib/analytics/compliance/display.ts

@@ -29,9 +29,9 @@ import {
 } from "./windows";
 import {
   COMPLIANCE_LEDGER_WINDOW_DAYS,
-  buildComplianceLedgerRows,
   tallyComplianceFromLedger,
-  tallyLedgerRows,
+  trailingComplianceLedger,
+  trailingComplianceTally,
 } from "./ledger";
 import { buildCurrentCycle, type CurrentCycle } from "./cycle";
 import { rollingIntakeInstants } from "./adapters";
@@ -564,9 +564,7 @@ export function buildMedicationComplianceBundle(
       : ledgerPeriodStart;
 
   const hasSchedules = schedules.length > 0;
-  const ledgerRows = hasSchedules
-    ? buildComplianceLedgerRows(events, schedules, ctx, ledgerFrom, now, now)
-    : [];
+  const ledgerRows = trailingComplianceLedger(events, schedules, ctx, now);
 
   // ONE cadence timeline over the full ledger window. Each per-window
   // streak below walks only its own trailing `effectiveDays`, so sharing
@@ -607,10 +605,7 @@ export function buildMedicationComplianceBundle(
       1,
       Math.ceil((now.getTime() - effectiveStart.getTime()) / ONE_DAY_MS),
     );
-    const tally = tallyLedgerRows(ledgerRows, {
-      from: periodStart,
-      to: now,
-    });
+    const tally = trailingComplianceTally(ledgerRows, days, now);
     const { current: streak } = streaksFromTimeline(
       timeline,
       now,

src/lib/analytics/compliance/ledger.ts

@@ -306,6 +306,41 @@ export function tallyLedgerRows(
  */
 export const COMPLIANCE_LEDGER_WINDOW_DAYS = 365;
 
+/**
+ * The ledger over the trailing {@link COMPLIANCE_LEDGER_WINDOW_DAYS} ending at
+ * `now`: the one set of dose rows every per-medication compliance figure is
+ * tallied from. A slot before the medication's creation stays in it only when
+ * a recorded dose claims it (#1028).
+ */
+export function trailingComplianceLedger(
+  events: IntakeEvent[],
+  schedules: ComplianceSchedule[],
+  ctx: ComplianceMedicationContext,
+  now: Date,
+): DoseHistoryRow[] {
+  if (schedules.length === 0) return [];
+  const from = new Date(
+    now.getTime() - COMPLIANCE_LEDGER_WINDOW_DAYS * 24 * 60 * 60 * 1000,
+  );
+  return buildComplianceLedgerRows(events, schedules, ctx, from, now, now);
+}
+
+/**
+ * The tally of the trailing `days` ending at `now`, carved out of
+ * {@link trailingComplianceLedger}: the same rows, so the same window reads
+ * the same rate on every surface.
+ */
+export function trailingComplianceTally(
+  ledger: DoseHistoryRow[],
+  days: number,
+  now: Date,
+): LedgerComplianceTally {
+  return tallyLedgerRows(ledger, {
+    from: new Date(now.getTime() - days * 24 * 60 * 60 * 1000),
+    to: now,
+  });
+}
+
 /**
  * One day of the cadence-aware compliance series: the day's compliance %
  * over the doses the schedule actually expected that day, plus the raw

src/lib/medications/scheduling/__tests__/compliance.test.ts

@@ -8,16 +8,29 @@
 import { describe, expect, it } from "vitest";
 import { complianceChips, streaksFromTimeline } from "../compliance";
 import { buildCadenceTimeline } from "../cadence";
-import type {
-  CadenceEngineContext,
-  IntakeEventLike,
-  ScheduleLike,
-} from "../cadence";
+import type { IntakeEventLike, ScheduleLike } from "../cadence";
+import type { ComplianceMedicationContext } from "@/lib/analytics/compliance/types";
+import { buildMedicationComplianceBundle } from "@/lib/analytics/compliance/display";
 
 function d(iso: string): Date {
   return new Date(iso);
 }
 
+/** The medication context the chips read; UTC unless a test says otherwise. */
+function ctx(
+  over?: Partial<ComplianceMedicationContext>,
+): ComplianceMedicationContext {
+  return {
+    startsOn: null,
+    endsOn: null,
+    oneShot: false,
+    createdAt: d("2025-05-01T00:00:00Z"),
+    lastIntakeAt: null,
+    timeZone: "UTC",
+    ...over,
+  };
+}
+
 const DAILY_8AM: ScheduleLike = {
   windowStart: "08:00",
   windowEnd: "09:00",
@@ -27,7 +40,7 @@ const DAILY_8AM: ScheduleLike = {
 describe("complianceChips", () => {
   it("returns null adherence when no doses are expected in the window", () => {
     const NOW = d("2025-06-10T12:00:00");
-    const result = complianceChips([], [], NOW, 30);
+    const result = complianceChips([], [], ctx(), NOW, 30);
     expect(result.adherenceRate).toBeNull();
     expect(result.missedLast30).toBe(0);
   });
@@ -44,14 +57,14 @@ describe("complianceChips", () => {
     }
     // 5-day window: 5 expected, 5 taken, 0 missed (today's slot is upcoming
     // because NOW is 12:00 and window is 08:00-09:00... actually past today)
-    const result = complianceChips([DAILY_8AM], events, NOW, 5);
+    const result = complianceChips([DAILY_8AM], events, ctx(), NOW, 5);
     expect(result.adherenceRate).toBeGreaterThanOrEqual(80);
     expect(result.missedLast30).toBeLessThanOrEqual(1);
   });
 
   it("computes 0% adherence when no events match any past slot", () => {
     const NOW = d("2025-06-10T12:00:00");
-    const result = complianceChips([DAILY_8AM], [], NOW, 5);
+    const result = complianceChips([DAILY_8AM], [], ctx(), NOW, 5);
     expect(result.adherenceRate).toBe(0);
     expect(result.missedLast30).toBeGreaterThan(0);
   });
@@ -60,25 +73,25 @@ describe("complianceChips", () => {
     const NOW = d("2025-06-10T12:00:00");
     // Window: NOW - 3d = 2025-06-07T12:00 → past slots: 08, 09, 10
     // Provide one taken + one skipped + one taken for the three slots so
-    // the denominator excludes the skipped one.
+    // the denominator excludes the skipped one. A skip names its slot.
     const events: IntakeEventLike[] = [
       {
-        scheduledFor: d("2025-06-08T08:30:00"),
+        scheduledFor: d("2025-06-08T08:00:00"),
         takenAt: d("2025-06-08T08:35:00"),
         skipped: false,
       },
       {
-        scheduledFor: d("2025-06-09T08:30:00"),
+        scheduledFor: d("2025-06-09T08:00:00"),
         takenAt: null,
         skipped: true,
       },
       {
-        scheduledFor: d("2025-06-10T08:30:00"),
+        scheduledFor: d("2025-06-10T08:00:00"),
         takenAt: d("2025-06-10T08:35:00"),
         skipped: false,
       },
     ];
-    const result = complianceChips([DAILY_8AM], events, NOW, 3);
+    const result = complianceChips([DAILY_8AM], events, ctx(), NOW, 3);
     // 2 taken / (2 taken + 0 missed) = 100, skipped excluded.
     expect(result.adherenceRate).toBe(100);
   });
@@ -97,7 +110,7 @@ describe("complianceChips", () => {
         skipped: false,
       });
     }
-    const result = complianceChips([DAILY_8AM], events, NOW, 14);
+    const result = complianceChips([DAILY_8AM], events, ctx(), NOW, 14);
     expect(result.currentStreak).toBeGreaterThanOrEqual(4);
   });
 
@@ -132,7 +145,7 @@ describe("complianceChips", () => {
         skipped: false,
       },
     ];
-    const result = complianceChips([DAILY_8AM], events, NOW, 7);
+    const result = complianceChips([DAILY_8AM], events, ctx(), NOW, 7);
     // Streak ending at today = day 9 + day 10 = 2 (day 8 missed broke it).
     expect(result.currentStreak).toBeLessThanOrEqual(2);
     // Longest streak in window = max(3 from 5..7, 2 from 9..10) = 3.
@@ -158,7 +171,7 @@ describe("complianceChips", () => {
         skipped: false,
       },
     ];
-    const result = complianceChips([weekly], events, NOW, 14);
+    const result = complianceChips([weekly], events, ctx(), NOW, 14);
     expect(result.adherenceRate).toBe(100);
     expect(result.missedLast30).toBe(0);
   });
@@ -170,7 +183,7 @@ describe("complianceChips", () => {
       daysOfWeek: "1", // Monday only
     };
     const NOW = d("2025-06-10T12:00:00"); // Tuesday
-    const result = complianceChips([weekly], [], NOW, 14);
+    const result = complianceChips([weekly], [], ctx(), NOW, 14);
     expect(result.adherenceRate).toBe(0);
     expect(result.missedLast30).toBeGreaterThan(0);
   });
@@ -199,18 +212,16 @@ describe("complianceChips", () => {
     const berlin = complianceChips(
       [sched],
       events,
+      ctx({ timeZone: "Europe/Berlin" }),
       NOW,
       7,
-      undefined,
-      "Europe/Berlin",
     );
     const tokyo = complianceChips(
       [sched],
       events,
+      ctx({ timeZone: "Asia/Tokyo" }),
       NOW,
       7,
-      undefined,
-      "Asia/Tokyo",
     );
 
     // Both must compute a finite adherence rate (the schedule has
@@ -226,23 +237,10 @@ describe("complianceChips", () => {
 });
 
 describe("complianceChips — canonical-engine delegation (v1.7.0 SB-SCHED-2)", () => {
-  function engineCtx(
-    over?: Partial<CadenceEngineContext>,
-  ): CadenceEngineContext {
-    return {
-      startsOn: null,
-      endsOn: null,
-      oneShot: false,
-      createdAt: d("2025-05-01T00:00:00Z"),
-      lastIntakeAt: null,
-      timeZone: "Europe/Berlin",
-      ...over,
-    };
-  }
+  const engineCtx = (over?: Partial<ComplianceMedicationContext>) =>
+    ctx({ timeZone: "Europe/Berlin", ...over });
 
-  it("RRULE weekly Monday: legacy walker counts every day missed, engine counts only Mondays", () => {
-    // `daysOfWeek = null` reads as every-day to the legacy walker, so an
-    // RRULE-weekly schedule over-counts expected doses without the engine.
+  it("RRULE weekly Monday: only the Mondays in the window are expected", () => {
     const rruleWeekly: ScheduleLike = {
       windowStart: "08:00",
       windowEnd: "09:00",
@@ -250,25 +248,15 @@ describe("complianceChips — canonical-engine delegation (v1.7.0 SB-SCHED-2)",
       rrule: "FREQ=WEEKLY;BYDAY=MO",
       timesOfDay: ["08:00"],
     };
-    const NOW = d("2025-06-10T12:00:00Z"); // Tuesday
+    // Saturday: both Mondays in the window are past a weekly dose's late tail.
+    const NOW = d("2025-06-14T12:00:00Z");
 
-    // Legacy path (no engineCtx) expands daily → many missed days.
-    const legacy = complianceChips([rruleWeekly], [], NOW, 14);
-    // Canonical path (engineCtx) expands only Mondays in the window.
-    const engine = complianceChips(
-      [rruleWeekly],
-      [],
-      NOW,
-      14,
-      undefined,
-      "Europe/Berlin",
-      engineCtx(),
-    );
+    const engine = complianceChips([rruleWeekly], [], engineCtx(), NOW, 14);
 
-    // The engine path expects far fewer doses (only the Mondays in a
-    // 14-day window: 2) than the daily legacy expansion (~13).
-    expect(engine.missedLast30).toBeLessThan(legacy.missedLast30);
-    expect(engine.missedLast30).toBeLessThanOrEqual(2);
+    // Two Mondays in a 14-day window, both missed; `daysOfWeek = null`
+    // must not read as every day.
+    expect(engine.missedLast30).toBe(2);
+    expect(engine.adherenceRate).toBe(0);
   });
 
   it("PRN: engine short-circuits to zero expected doses (no adherence, no missed)", () => {
@@ -281,15 +269,7 @@ describe("complianceChips — canonical-engine delegation (v1.7.0 SB-SCHED-2)",
     };
     const NOW = d("2025-06-10T12:00:00Z");
 
-    const engine = complianceChips(
-      [prn],
-      [],
-      NOW,
-      30,
-      undefined,
-      "Europe/Berlin",
-      engineCtx(),
-    );
+    const engine = complianceChips([prn], [], engineCtx(), NOW, 30);
 
     // PRN is as-needed — never projected, reminded, or counted in
     // compliance-expected. No expected slots → null adherence, zero missed.
@@ -315,20 +295,16 @@ describe("complianceChips — canonical-engine delegation (v1.7.0 SB-SCHED-2)",
     const engine = complianceChips(
       [cyclic],
       [],
+      engineCtx({ startsOn: d("2025-05-01T00:00:00Z") }),
       NOW,
       14,
-      undefined,
-      "Europe/Berlin",
-      engineCtx({ startsOn: d("2025-05-01T00:00:00Z") }),
     );
     const everyDay = complianceChips(
       [{ ...cyclic, scheduleType: "SCHEDULED" }],
       [],
+      engineCtx({ startsOn: d("2025-05-01T00:00:00Z") }),
       NOW,
       14,
-      undefined,
-      "Europe/Berlin",
-      engineCtx({ startsOn: d("2025-05-01T00:00:00Z") }),
     );
 
     // The cyclic gate must drop the off-week's doses, so fewer missed
@@ -445,3 +421,43 @@ describe("streaksFromTimeline — DST-correct day walk", () => {
     expect(current).toBe(7);
   });
 });
+
+describe("complianceChips — the detail page's rate", () => {
+  it("drops a pause from the chips exactly as the compliance payload does", () => {
+    // Daily 08:00, paused from 10 days ago to 3 days ago, every other dose
+    // taken. The chips used to tally the paused week as seven missed doses
+    // (77 %) while the detail page, reading the compliance ledger, said 100.
+    const NOW = d("2025-06-30T12:00:00Z");
+    const day = (n: number) => new Date(NOW.getTime() - n * 86_400_000);
+    const pausedAt = day(10);
+    const resumedAt = day(3);
+    const events: IntakeEventLike[] = [];
+    for (let n = 1; n <= 30; n++) {
+      const slot = new Date(day(n).setUTCHours(8, 0, 0, 0));
+      if (slot >= pausedAt && slot < resumedAt) continue;
+      events.push({ scheduledFor: slot, takenAt: slot, skipped: false });
+    }
+    const daily: ScheduleLike = {
+      windowStart: "08:00",
+      windowEnd: "09:00",
+      daysOfWeek: null,
+      timesOfDay: ["08:00"],
+    };
+    const context = ctx({
+      createdAt: d("2025-01-01T00:00:00Z"),
+      pauseEras: [{ pausedAt, resumedAt }],
+    });
+
+    const chips = complianceChips([daily], events, context, NOW, 30);
+    const bundle = buildMedicationComplianceBundle(
+      events,
+      [daily],
+      context,
+      NOW,
+    );
+
+    expect(chips.missedLast30).toBe(0);
+    expect(chips.adherenceRate).toBe(100);
+    expect(chips.adherenceRate).toBe(bundle.compliance30.rate);
+  });
+});

src/lib/medications/scheduling/compliance.ts

@@ -6,33 +6,28 @@
  * rate, current streak (days), longest streak (days), missed in last
  * 30 days. Each chip is monochrome — maintainer note: no gamified badges.
  *
- * Distinct from `src/lib/analytics/compliance.ts.calculateCompliance`:
- * that helper computes against expected counts (schedules-per-day ×
- * days) and is used by the existing /api/medications/[id]/compliance
- * route. This module computes against the pair-matched timeline so
- * the chips and the cadence chart agree on every single dose.
+ * Adherence and missed doses come from the compliance ledger the
+ * /api/medications/[id]/compliance route reads, so the chips and the
+ * detail page's rate agree; the streaks walk the pair-matched timeline
+ * the cadence chart draws.
  *
- * v1.4.25 W21 Fix-O — accepts an optional IANA `timeZone` argument
- * forwarded into the timeline + streak math so a user in Tokyo gets
- * the same chip values as a user in Berlin even when the host's
- * system time is set differently. Omitting the argument keeps the
- * legacy system-local behaviour the W19e tests pin.
+ * The timeline and streak math run in the context's IANA zone, so a user
+ * in Tokyo gets the same chip values as a user in Berlin whatever the
+ * host's system time is.
  */
 
-import type { SlotBand } from "./attribution";
-import { type BandMinterMedication } from "./band-minter";
-import { buildBandsForSchedulesWithEras } from "./schedule-eras";
 import {
   buildCadenceTimeline,
   startOfLocalDay,
-  type CadenceEngineContext,
   type IntakeEventLike,
   type PairedDose,
   type ScheduleLike,
 } from "./cadence";
-import { reconstructDoseHistory, type HistoryIntake } from "./dose-history";
-import { type CanonicalSchedule, type RecurrenceContext } from "./recurrence";
-import { normaliseDoseWindows } from "./worker-helpers";
+import {
+  trailingComplianceLedger,
+  trailingComplianceTally,
+} from "@/lib/analytics/compliance/ledger";
+import type { ComplianceMedicationContext } from "@/lib/analytics/compliance/types";
 import { userDayKey } from "@/lib/tz/resolver";
 
 export interface ComplianceChips {
@@ -146,134 +141,19 @@ export function streaksFromTimeline(
 }
 
 /**
- * v1.15.18 — band-ledger tally counts for the detail-page chips.
- *
- * When the route threads an engine context (RRULE / rolling / cyclic /
- * one-shot / PRN / legacy) the adherence rate + missed count come from the
- * SAME unified dose-history ledger the compliance % and the history view
- * read — so the chips can never contradict either. The streak still walks
- * the cadence timeline (its day-grain "every dose taken or skipped" rule is
- * orthogonal to per-dose attribution). Returns null when there is no engine
- * context (a pure-math caller) — the caller then falls back to the legacy
- * timeline tally.
+ * The four chips: adherence and missed doses from the compliance ledger the
+ * detail page's rate reads (`trailingComplianceTally`, with the medication's
+ * pause eras and courses), the streaks from the cadence timeline (a
+ * day-grain "every dose taken or skipped" rule, orthogonal to per-dose
+ * attribution).
  */
-function ledgerChipCounts(
-  schedules: ScheduleLike[],
-  events: IntakeEventLike[],
-  asOf: Date,
-  windowDays: number,
-  timeZone: string | undefined,
-  engineCtx: CadenceEngineContext | undefined,
-): { taken: number; missed: number } | null {
-  if (!engineCtx) return null;
-  const DAY_MS = 24 * 60 * 60 * 1000;
-  const from = new Date(asOf.getTime() - windowDays * DAY_MS);
-  const userTz = engineCtx.timeZone || timeZone || "UTC";
-
-  const medication: BandMinterMedication = {
-    id: "chips-tally",
-    startsOn: engineCtx.startsOn,
-    endsOn: engineCtx.endsOn,
-    oneShot: engineCtx.oneShot,
-    createdAt: engineCtx.createdAt,
-  };
-  const recurrenceCtx: RecurrenceContext = {
-    medication: {
-      id: "chips-tally",
-      startsOn: engineCtx.startsOn,
-      endsOn: engineCtx.endsOn,
-      oneShot: engineCtx.oneShot,
-      createdAt: engineCtx.createdAt,
-    },
-    timeZone: userTz,
-    lastIntakeAt: engineCtx.lastIntakeAt,
-    // v1.40 (#1024) — a medication: `startsOn` is a course start.
-    rollingAnchor: "courseStart",
-  };
-  const canonicalSchedules: CanonicalSchedule[] = schedules.map((s, i) => {
-    const base: CanonicalSchedule = {
-      id: s.id ?? `chips-${i}`,
-      rrule: s.rrule ?? null,
-      rollingIntervalDays: s.rollingIntervalDays ?? null,
-      timesOfDay: s.timesOfDay ?? [],
-      daysOfWeek: s.daysOfWeek ?? null,
-      windowStart: s.windowStart,
-      windowEnd: s.windowEnd,
-      reminderGraceMinutes: s.reminderGraceMinutes ?? null,
-      scheduleType: s.scheduleType ?? "SCHEDULED",
-      cyclicOnWeeks: s.cyclicOnWeeks ?? null,
-      cyclicOffWeeks: s.cyclicOffWeeks ?? null,
-      doseWindows: normaliseDoseWindows(s.doseWindows),
-    };
-    // Surface windowStart as the single time-of-day for a legacy daily row
-    // so the band minter's cadence gate mints its daily band (see the
-    // analytics/compliance tally for the same normalisation).
-    if (
-      base.timesOfDay.length === 0 &&
-      base.rrule === null &&
-      base.rollingIntervalDays === null &&
-      base.scheduleType !== "PRN" &&
-      !engineCtx.oneShot
-    ) {
-      return { ...base, timesOfDay: [base.windowStart] };
-    }
-    return base;
-  });
-
-  const intakeInstants = events
-    .filter((e) => !e.skipped && e.takenAt !== null && e.takenAt <= asOf)
-    .map((e) => e.takenAt as Date)
-    .sort((a, b) => a.getTime() - b.getTime());
-
-  const groups = buildBandsForSchedulesWithEras({
-    medication,
-    schedules: canonicalSchedules,
-    revisions: engineCtx.scheduleRevisions ?? [],
-    ctx: recurrenceCtx,
-    userTz,
-    range: { from, to: asOf },
-    now: asOf,
-    intakeInstants,
-  });
-  const bands: SlotBand[] = [];
-  for (const g of groups) {
-    if (g.hasExpectedSlots) bands.push(...g.bands);
-  }
-
-  const intakes: HistoryIntake[] = events
-    .filter((e) => e.scheduledFor >= from && e.scheduledFor <= asOf)
-    .map((e) => ({
-      scheduledFor: e.scheduledFor,
-      takenAt: e.takenAt,
-      skipped: e.skipped,
-      autoMissed: e.autoMissed ?? false,
-      // v1.15.20 — pinned takes bind by anchor (taken-late, slot served).
-      pinned: e.attributionSource === "USER_PIN",
-    }));
-
-  const rows = reconstructDoseHistory(
-    bands,
-    intakes,
-    asOf,
-    engineCtx.createdAt,
-  );
-  let taken = 0;
-  let missed = 0;
-  for (const row of rows) {
-    if (row.status === "taken_on_time" || row.status === "taken_late") taken++;
-    else if (row.status === "missed") missed++;
-  }
-  return { taken, missed };
-}
-
 export function complianceChips(
   schedules: ScheduleLike[],
   events: IntakeEventLike[],
+  ctx: ComplianceMedicationContext,
   asOf: Date,
   windowDays = 30,
   anchor?: Date,
-  timeZone?: string,
-  engineCtx?: CadenceEngineContext,
 ): ComplianceChips {
   const timeline = buildCadenceTimeline(
     schedules,
@@ -281,33 +161,21 @@ export function complianceChips(
     asOf,
     windowDays,
     anchor,
-    timeZone,
-    engineCtx,
+    ctx.timeZone,
+    ctx,
   );
-  // v1.15.18 — adherence + missed come from the unified band ledger when an
-  // engine context is present (so the chips agree with the % and the history
-  // view); the legacy timeline tally is the fallback for pure-math callers.
-  const ledger = ledgerChipCounts(
-    schedules,
-    events,
-    asOf,
+  const { taken, missed } = trailingComplianceTally(
+    trailingComplianceLedger(events, schedules, ctx, asOf),
     windowDays,
-    timeZone,
-    engineCtx,
+    asOf,
   );
-  const taken = ledger
-    ? ledger.taken
-    : timeline.filter((d) => d.status === "taken").length;
-  const missed = ledger
-    ? ledger.missed
-    : timeline.filter((d) => d.status === "missed").length;
   const denom = taken + missed;
   const adherenceRate = denom === 0 ? null : Math.round((taken / denom) * 100);
   const { current, longest } = streaksFromTimeline(
     timeline,
     asOf,
     windowDays,
-    timeZone,
+    ctx.timeZone,
   );
   return {
     adherenceRate,