refactor(tz): take the medication and reminder trees off the zone literal

The medication and measurement-reminder code now imports DEFAULT_TIMEZONE
from the tz module like every other fallback, so the lint rule no longer
exempts those paths.

src/app/api/measurement-reminders/[id]/complete/route.ts

@@ -30,11 +30,10 @@ import { annotate } from "@/lib/logging/context";
 import { satisfyReminder } from "@/lib/measurement-reminders/satisfy";
 import { toMeasurementReminderDto } from "@/lib/measurement-reminders/dto";
 import { isScreeningReminderType } from "@/lib/validations/measurement-reminders";
+import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 
 type RouteParams = { params: Promise<{ id: string }> };
 
-const DEFAULT_TIMEZONE = "Europe/Berlin";
-
 export const POST = apiHandler(
   async (request: NextRequest, { params }: RouteParams) => {
     // v1.37.0 — MANAGE. Marking a reminder satisfied re-anchors a schedule the level

src/app/api/measurement-reminders/[id]/route.ts

@@ -33,13 +33,11 @@ import {
 } from "@/lib/measurement-reminders/scheduling";
 import { toMeasurementReminderDto } from "@/lib/measurement-reminders/dto";
 import { wallClockInTz, zonedWallClockToUtc } from "@/lib/tz/wall-clock";
-import { userDayKey } from "@/lib/tz/format";
+import { DEFAULT_TIMEZONE, userDayKey } from "@/lib/tz/format";
 import { holdsOpenAfterReminder } from "@/lib/measurement-reminders/holds-open";
 
 type RouteParams = { params: Promise<{ id: string }> };
 
-const DEFAULT_TIMEZONE = "Europe/Berlin";
-
 async function resolveTimezone(userId: string): Promise<string> {
   const row = await prisma.user.findUnique({
     where: { id: userId },

src/app/api/measurement-reminders/[id]/satisfy/route.ts

@@ -16,11 +16,10 @@ import { annotate } from "@/lib/logging/context";
 import { satisfyReminder } from "@/lib/measurement-reminders/satisfy";
 import { toMeasurementReminderDto } from "@/lib/measurement-reminders/dto";
 import { isScreeningReminderType } from "@/lib/validations/measurement-reminders";
+import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 
 type RouteParams = { params: Promise<{ id: string }> };
 
-const DEFAULT_TIMEZONE = "Europe/Berlin";
-
 export const POST = apiHandler(
   async (request: NextRequest, { params }: RouteParams) => {
     // v1.37.0 — MANAGE. The same primitive from the checklist side re-anchors a schedule the level

src/app/api/measurement-reminders/[id]/skip/route.ts

@@ -22,11 +22,10 @@ import { apiSuccess, apiError, getClientIp } from "@/lib/api-response";
 import { annotate } from "@/lib/logging/context";
 import { skipReminder } from "@/lib/measurement-reminders/satisfy";
 import { toMeasurementReminderDto } from "@/lib/measurement-reminders/dto";
+import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 
 type RouteParams = { params: Promise<{ id: string }> };
 
-const DEFAULT_TIMEZONE = "Europe/Berlin";
-
 export const POST = apiHandler(
   async (request: NextRequest, { params }: RouteParams) => {
     // MANAGE — the same level as satisfy/complete: deciding to let a cycle

src/app/api/measurement-reminders/[id]/snooze/route.ts

@@ -29,11 +29,10 @@ import { annotate } from "@/lib/logging/context";
 import { toMeasurementReminderDto } from "@/lib/measurement-reminders/dto";
 import { snoozeMeasurementReminderSchema } from "@/lib/validations/measurement-reminders";
 import { zonedWallClockToUtc } from "@/lib/tz/wall-clock";
+import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 
 type RouteParams = { params: Promise<{ id: string }> };
 
-const DEFAULT_TIMEZONE = "Europe/Berlin";
-
 /** Furthest a snooze may reach: five years from now. */
 const SNOOZE_CAP_MS = 5 * 365.25 * 24 * 60 * 60 * 1000;
 

src/app/api/measurement-reminders/route.ts

@@ -25,8 +25,7 @@ import {
 } from "@/lib/measurement-reminders/scheduling";
 import { toMeasurementReminderDto } from "@/lib/measurement-reminders/dto";
 import { listMeasurementReminders } from "@/lib/measurement-reminders/list-read";
-
-const DEFAULT_TIMEZONE = "Europe/Berlin";
+import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 
 async function resolveTimezone(userId: string): Promise<string> {
   const row = await prisma.user.findUnique({

src/lib/jobs/measurement-reminder.ts

@@ -59,6 +59,7 @@ import { satisfyReminder } from "@/lib/measurement-reminders/satisfy";
 import { evaluateCoachContextReminders } from "@/lib/ai/coach/context-reminders";
 import { calendarDaysUntil } from "@/lib/measurement-reminders/due-day";
 import { holdsOpenAfterReminder } from "@/lib/measurement-reminders/holds-open";
+import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 
 /**
  * v1.18.0 — map a reminder's `measurementType` to the toggleable module
@@ -231,7 +232,7 @@ export function evaluateMeasurementReminderDue(
   if (!reminder.enabled || reminder.nextDueAt === null) {
     return { fire: false, inHourWindow: false, isDue: false };
   }
-  const tz = timezone || "Europe/Berlin";
+  const tz = timezone || DEFAULT_TIMEZONE;
   const isDue = now.getTime() >= reminder.nextDueAt.getTime();
   const parts = wallClockInTz(now, tz);
   const inHourWindow = parts.hour === reminderSlotHour(reminder, tz);
@@ -326,7 +327,7 @@ export async function runMeasurementReminderTick(
   for (const reminder of reminders) {
     summary.candidatesScanned += 1;
     try {
-      const timezone = reminder.user.timezone || "Europe/Berlin";
+      const timezone = reminder.user.timezone || DEFAULT_TIMEZONE;
 
       // v1.39.2 — a reminder already sent for its current slot stays in
       // this scan every tick until it is satisfied. Outside its notify hour
@@ -587,7 +588,7 @@ export async function runReminderSatisfyForUser(
     where: { id: userId },
     select: { timezone: true },
   });
-  const timezone = user?.timezone || "Europe/Berlin";
+  const timezone = user?.timezone || DEFAULT_TIMEZONE;
 
   const reminders = await prisma.measurementReminder.findMany({
     where: { userId, deletedAt: null, enabled: true },

src/lib/measurement-reminders/scheduling.ts

@@ -30,6 +30,7 @@ import {
   nextOccurrenceAfter,
 } from "@/lib/medications/scheduling/recurrence";
 import { wallClockInTz } from "@/lib/tz/wall-clock";
+import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 
 /**
  * The reminder fields this module reads. A subset of the Prisma row so
@@ -133,7 +134,7 @@ export function buildReminderRecurrence(
   // `anchorDate` / `endsOn` are instants instead (the form sends local
   // midnight, a Coach course sends `now + days`), so hand the engine the
   // calendar day each instant falls on in the user's zone.
-  const tz = timeZone || "Europe/Berlin";
+  const tz = timeZone || DEFAULT_TIMEZONE;
   const startsOn = calendarDayInZone(
     reminder.anchorDate ?? reminder.createdAt,
     tz,

src/lib/medications/default-medication.ts

@@ -2,6 +2,7 @@ import {
   reduceCurrentWindowStatus,
   type ScheduleWindowInput,
 } from "@/lib/medications/window-status";
+import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 
 export interface DefaultMedicationOption {
   id: string;
@@ -24,8 +25,6 @@ const DEFAULT_THRESHOLDS: MedicationDueThresholds = {
   missedMinutes: 240,
 };
 
-const DEFAULT_TIMEZONE = "Europe/Berlin";
-
 /**
  * Pick the medication that should be pre-selected when an intake form opens.
  * Current, late, and overdue schedule windows win; otherwise the fallback is

src/lib/medications/list-read.ts

@@ -35,6 +35,7 @@ import {
 } from "@/lib/medications/intake-tracking";
 import { liveEraStartsByMedication } from "@/lib/medications/scheduling/live-era";
 import { floorWhole } from "@/lib/medications/units-per-dose";
+import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 
 export type MedicationsListResult = Array<Record<string, unknown>>;
 
@@ -327,7 +328,7 @@ export async function readMedicationsListCached(user: {
   id: string;
   timezone: string | null;
 }): Promise<MedicationsListResult> {
-  const userTz = user.timezone || "Europe/Berlin";
+  const userTz = user.timezone || DEFAULT_TIMEZONE;
   return cachedSwr(
     caches.medications as ServerCache<MedicationsListResult>,
     user.id,

src/lib/medications/window-status.ts

@@ -48,6 +48,7 @@ import {
   wallClockInTz,
   type WallClockParts,
 } from "@/lib/tz/wall-clock";
+import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 
 /** One explicit per-dose on-time window as the API serialises it. */
 export interface DoseWindowEntryInput {
@@ -123,9 +124,6 @@ export interface NextDueGate {
   overdue: boolean;
 }
 
-/** Fallback timezone until every call site threads the user's own. */
-const DEFAULT_TZ = "Europe/Berlin";
-
 /**
  * Minute-of-day an observer in the target zone reads off the wall clock.
  * Every band comparison below is minute-of-day arithmetic, so this is the
@@ -516,7 +514,7 @@ export function reduceCurrentWindowStatus<
     active,
     lastTakenAt,
     todayEventCount,
-    tz = DEFAULT_TZ,
+    tz = DEFAULT_TIMEZONE,
     nextDue,
   } = options;
   const nowParts = wallClockInTz(now, tz);