feat(medications): make low-stock alert reorder-lead-time aware

The low-stock alert fired when the projected runway dropped below the
user threshold (default 7 days). For a sparse cadence — a weekly
injection's 7-day floor is barely one dose-interval — the warning landed
with about one dose left, too late to reorder before the supply ran out.

Add an optional per-medication reorder lead time plus a user-level
default (0–60 days, default 10) and widen the alert trigger to
max(lowStockRunwayDays, leadDays + cadenceIntervalDays), so the warning
lands before the last dose for any cadence. Because the trigger is a
max() over the user floor it never shrinks anyone's current threshold; a
daily med with no lead keeps its prior boundary.

The push body and the card notice surface concrete dates — supply runs
out around <date>, reorder by <date> — with a last-dose informational
state and the days/units fallback when supply data is thin. Retire the
stale fixed 4-dose count threshold on the GLP-1 details endpoint and
route its card lowStock flag through the same runway evaluation so the
card and the daily cron agree. Surface the lead default in the low-stock
settings card with progressive disclosure; a single medication can
override it.

Additive schema: nullable Medication.reorderLeadDays (migration 0161, no
backfill) and notificationPrefs.medication.reorderLeadDays. OpenAPI
regenerated.

src/app/api/settings/reminder-thresholds/__tests__/route.test.ts

@@ -77,12 +77,15 @@ describe("GET /api/settings/reminder-thresholds", () => {
         lateMinutes: number;
         missedMinutes: number;
         lowStockRunwayDays: number | null;
+        reorderLeadDays: number;
       };
     };
     expect(env.data).toEqual({
       lateMinutes: 120,
       missedMinutes: 240,
       lowStockRunwayDays: 7,
+      // v1.17.0 — the per-user reorder lead default rides along.
+      reorderLeadDays: 10,
     });
   });
 

src/app/api/settings/reminder-thresholds/route.ts

@@ -3,7 +3,7 @@ import { getReminderThresholds } from "@/lib/app-settings";
 import { apiHandler, requireAuth } from "@/lib/api-handler";
 import { annotate } from "@/lib/logging/context";
 import { prisma } from "@/lib/db";
-import { resolveLowStockRunwayDays } from "@/lib/validations/notification-prefs";
+import { parseNotificationPrefs } from "@/lib/validations/notification-prefs";
 
 export const dynamic = "force-dynamic";
 
@@ -22,11 +22,15 @@ export const GET = apiHandler(async () => {
     where: { id: user.id },
     select: { notificationPrefs: true },
   });
-  const lowStockRunwayDays = resolveLowStockRunwayDays(
-    row?.notificationPrefs ?? null,
-  );
+  const prefs = parseNotificationPrefs(row?.notificationPrefs ?? null);
+  const lowStockRunwayDays = prefs.medication.lowStockRunwayDays;
+  // v1.17.0 — the user-level reorder lead default rides along so the
+  // medication cards can derive the same reorder-lead-aware trigger the
+  // daily cron uses (per-medication overrides come from the list payload's
+  // own `reorderLeadDays`).
+  const reorderLeadDays = prefs.medication.reorderLeadDays;
 
   annotate({ action: { name: "settings.reminder-thresholds.get" } });
 
-  return apiSuccess({ ...thresholds, lowStockRunwayDays });
+  return apiSuccess({ ...thresholds, lowStockRunwayDays, reorderLeadDays });
 });