test(01-11): specify rolling weekly overdue identity

- pin the prior-day Mounjaro occurrence across local midnight and DST
- cover resolution state, band end, schedule siblings, and era isolation

src/lib/medications/scheduling/__tests__/next-due.test.ts

@@ -558,3 +558,144 @@ describe("as-needed (zero schedules) — never due", () => {
     expect(display).toBeNull();
   });
 });
+
+describe("Mounjaro rolling weekly — canonical overdue band after day change", () => {
+  const lastTaken = d("2026-07-21T06:00:00.000Z"); // Jul 21 08:00 Berlin
+  const missedOccurrence = d("2026-07-28T06:00:00.000Z"); // Jul 28 08:00
+  const nextOccurrence = d("2026-08-04T06:00:00.000Z"); // Aug 4 08:00
+  const medication = makeMedication({
+    startsOn: d("2026-01-01T00:00:00.000Z"),
+  });
+  const schedule = makeRollingSchedule({
+    id: "mounjaro-weekly",
+    timesOfDay: ["08:00"],
+  });
+  const identifiedMark = (
+    at: Date,
+    identity: Record<string, unknown>,
+  ): ResolvedSlotMark =>
+    ({
+      ...mark(at),
+      ...identity,
+    }) as ResolvedSlotMark;
+
+  it("keeps yesterday's unresolved occurrence overdue on the following local day", () => {
+    const display = computeDisplayDue({
+      medication,
+      schedules: [schedule],
+      now: d("2026-07-29T10:00:00.000Z"),
+      userTz: BERLIN,
+      lastIntakeAt: lastTaken,
+      resolvedSlots: [],
+    });
+
+    expect(display).toMatchObject({
+      at: missedOccurrence,
+      overdue: true,
+    });
+  });
+
+  it("keeps the occurrence through the exact canonical band end, then closes it", () => {
+    const atBandEnd = computeDisplayDue({
+      medication,
+      schedules: [schedule],
+      now: d("2026-08-02T06:00:00.000Z"),
+      userTz: BERLIN,
+      lastIntakeAt: lastTaken,
+      resolvedSlots: [],
+    });
+    expect(atBandEnd).toMatchObject({
+      at: missedOccurrence,
+      overdue: true,
+    });
+
+    const afterBandEnd = computeDisplayDue({
+      medication,
+      schedules: [schedule],
+      now: d("2026-08-02T06:00:00.001Z"),
+      userTz: BERLIN,
+      lastIntakeAt: lastTaken,
+      resolvedSlots: [],
+    });
+    expect(afterBandEnd).toBeNull();
+  });
+
+  it.each(["taken", "skipped", "autoMissed"] as const)(
+    "an exact %s row suppresses only this occurrence and advances",
+    (status) => {
+      const display = computeDisplayDue({
+        medication,
+        schedules: [schedule],
+        now: d("2026-07-29T10:00:00.000Z"),
+        userTz: BERLIN,
+        lastIntakeAt:
+          status === "taken"
+            ? d("2026-07-28T06:10:00.000Z")
+            : lastTaken,
+        resolvedSlots: [
+          identifiedMark(missedOccurrence, {
+            scheduleId: "mounjaro-weekly",
+            status,
+          }),
+        ],
+      });
+
+      expect(display).toMatchObject({
+        at: nextOccurrence,
+        overdue: false,
+      });
+    },
+  );
+
+  it("does not let a sibling schedule's resolved occurrence suppress this schedule", () => {
+    const sibling = makeRollingSchedule({
+      id: "mounjaro-sibling",
+      timesOfDay: ["10:00"],
+      windowStart: "10:00",
+      windowEnd: "10:00",
+    });
+    const display = computeDisplayDue({
+      medication,
+      schedules: [schedule, sibling],
+      now: d("2026-07-29T10:00:00.000Z"),
+      userTz: BERLIN,
+      lastIntakeAt: lastTaken,
+      resolvedSlots: [
+        identifiedMark(missedOccurrence, {
+          scheduleId: "mounjaro-weekly",
+          status: "skipped",
+        }),
+      ],
+    });
+
+    expect(display).toMatchObject({
+      at: d("2026-07-28T08:00:00.000Z"),
+      overdue: true,
+      scheduleId: "mounjaro-sibling",
+    });
+  });
+
+  it("does not let an action from the archived era suppress the live-era occurrence", () => {
+    const liveEraStart = d("2026-07-27T12:00:00.000Z");
+    const display = computeDisplayDue({
+      medication,
+      schedules: [schedule],
+      now: d("2026-07-29T10:00:00.000Z"),
+      userTz: BERLIN,
+      lastIntakeAt: lastTaken,
+      eraStart: liveEraStart,
+      resolvedSlots: [
+        identifiedMark(missedOccurrence, {
+          scheduleId: "mounjaro-weekly",
+          actionAt: d("2026-07-27T11:59:59.000Z"),
+        }),
+      ],
+    });
+
+    expect(display).toMatchObject({
+      at: missedOccurrence,
+      overdue: true,
+      scheduleId: "mounjaro-weekly",
+    });
+  });
+});

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

@@ -473,6 +473,44 @@ describe("occurrencesBetween — rolling", () => {
   });
 });
 
+describe("rolling occurrence identity across a local-day change", () => {
+  it.each([
+    {
+      label: "ordinary Berlin week",
+      lastIntake: "2026-07-21T06:00:00.000Z",
+      now: "2026-07-29T10:00:00.000Z",
+      expected: "2026-07-28T06:00:00.000Z",
+    },
+    {
+      label: "Berlin spring DST week",
+      lastIntake: "2026-03-22T07:00:00.000Z",
+      now: "2026-03-30T10:00:00.000Z",
+      expected: "2026-03-29T06:00:00.000Z",
+    },
+  ])(
+    "retains the unresolved prior-day slot for an $label",
+    ({ lastIntake, now, expected }) => {
+      const schedule = makeSchedule({
+        id: "mounjaro-weekly",
+        rollingIntervalDays: 7,
+        timesOfDay: ["08:00"],
+      });
+      const ctx = makeCtx({
+        lastIntakeAt: d(lastIntake),
+        medication: { startsOn: d("2026-01-01T00:00:00.000Z") },
+      });
+
+      const occurrence = nextOccurrenceAfter(schedule, d(now), ctx);
+
+      expect(occurrence).toMatchObject({
+        scheduleId: "mounjaro-weekly",
+        at: d(expected),
+        timeOfDay: "08:00",
+      });
+    },
+  );
+});
+
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