fix(medications): make inventory Bestand summary server-authoritative

The medication detail clients computed the supply headline in the browser
via summariseSupply, risking web/iOS drift and pulling the shared math
into the client bundle. The GET /api/medications/[id]/inventory route now
computes the canonical SupplySummary server-side through summariseSupply
(the single source of truth) and ships it in the DTO; the Bestand and
Übersicht surfaces render the ready figures. Adds the MedicationSupplySummary
schema to the inventory list response and regenerates the OpenAPI contract.

src/components/medications/__tests__/inventory-section-summary.test.tsx

@@ -7,12 +7,19 @@
  * suffix — matching the list payload and the GLP-1 endpoint instead of
  * counting expired stock as supply.
  *
+ * v1.19.0 (iOS#25) — the headline is now server-authoritative: the GET
+ * response carries a `summary` computed server-side via `summariseSupply`,
+ * and the component RENDERS it (no client-side derivation). The seed
+ * builds that summary with the same canonical helper the server uses, so
+ * these scenarios assert the component renders the server DTO faithfully.
+ *
  * Project convention is SSR-only component tests (`renderToStaticMarkup`).
  */
 import { describe, expect, it, vi } from "vitest";
 import { renderToStaticMarkup } from "react-dom/server";
 
 import { I18nProvider } from "@/lib/i18n/context";
+import { summariseSupply } from "@/lib/medications/inventory/summary";
 
 const useQueryMock = vi.fn();
 
@@ -35,9 +42,27 @@ function render(node: React.ReactNode): string {
   );
 }
 
-function seedItems(items: unknown[]) {
+function seedItems(
+  items: Array<{
+    state: "ACTIVE" | "IN_USE" | "EXPIRED" | "USED_UP";
+    unitsTotal: number;
+    unitsRemaining: number;
+    [key: string]: unknown;
+  }>,
+  unitsPerDose = 1,
+) {
+  // The server computes the canonical summary; reproduce it here with the
+  // one source of truth so the seed mirrors the real DTO the route ships.
+  const summary = summariseSupply(
+    items.map((i) => ({
+      state: i.state,
+      unitsTotal: i.unitsTotal,
+      unitsRemaining: i.unitsRemaining,
+    })),
+    unitsPerDose,
+  );
   useQueryMock.mockReturnValue({
-    data: { items, meta: { total: items.length } },
+    data: { items, summary, meta: { total: items.length } },
     isLoading: false,
   });
 }

src/components/medications/detail/medication-detail-tabs.tsx

@@ -72,7 +72,7 @@ import { SideEffectsSection } from "@/components/medications/side-effects-sectio
 import { ChartSkeleton } from "@/components/charts/chart-skeleton";
 import { TitrationTimeline } from "@/components/medications/titration-timeline";
 import { estimateRunwayDays } from "@/components/medications/detail/supply-runway";
-import { summariseSupply } from "@/lib/medications/inventory/summary";
+import type { SupplySummary } from "@/lib/medications/inventory/summary";
 import { MedicationWizardDialog } from "@/components/medications/wizard/medication-wizard-dialog";
 import { parseScheduleRecurrence } from "@/lib/medication-schedule";
 import { useQuery } from "@tanstack/react-query";
@@ -335,9 +335,8 @@ export function MedicationDetailTabs({
         return await apiGet<{
           items: Array<{
             state: "ACTIVE" | "IN_USE" | "EXPIRED" | "USED_UP";
-            unitsTotal: number;
-            unitsRemaining: number;
           }>;
+          summary?: SupplySummary;
         } | null>(`/api/medications/${id}/inventory`);
       } catch {
         return null;
@@ -348,26 +347,34 @@ export function MedicationDetailTabs({
   });
 
   const inventoryItems = Array.isArray(inventory?.items) ? inventory.items : [];
-  // v1.16.10 — items count UNITS; the supply readout and the runway are
-  // dose-derived (floor over the pooled units — consumption spills
-  // across containers, so the pool is the honest dose count). The raw
-  // unit tally renders as secondary text when a dose spans > 1 unit.
-  // Availability rides the shared summary helper (ACTIVE / IN_USE with
-  // units only — the list / GLP-1 semantic); expired stock surfaces as
-  // a separate muted suffix and never feeds the runway.
-  // v1.16.12 — guard at > 0, NOT ≥ 1, so a fractional unitsPerDose (½
-  // tablet per dose) stays fractional instead of halving the dose counts.
-  const perDose =
-    medication.unitsPerDose && medication.unitsPerDose > 0
-      ? medication.unitsPerDose
-      : 1;
+  // v1.19.0 (iOS#25) — the supply headline is server-authoritative: the
+  // GET response carries a `summary` computed server-side through the
+  // shared `summariseSupply` helper (ACTIVE / IN_USE with units only —
+  // the list / GLP-1 semantic; EXPIRED surfaced separately, never
+  // available; dose-derived counts floored over the pooled units). The
+  // Übersicht status row renders these ready figures, so web and iOS read
+  // identical numbers from the same DTO. The runway estimate is a UI
+  // projection over the canonical `dosesRemaining`.
   const {
     unitsRemaining,
     unitsTotal,
     dosesRemaining,
     dosesTotal,
     expiredUnits,
-  } = summariseSupply(inventoryItems, perDose);
+  } = inventory?.summary ?? {
+    unitsRemaining: 0,
+    unitsTotal: 0,
+    dosesRemaining: 0,
+    dosesTotal: 0,
+    expiredUnits: 0,
+  };
+  // v1.16.12 — fractional unitsPerDose (½ tablet per dose) drives the
+  // "show the raw unit tally" toggle below; the canonical figures above
+  // already account for it server-side.
+  const perDose =
+    medication.unitsPerDose && medication.unitsPerDose > 0
+      ? medication.unitsPerDose
+      : 1;
   const runwayDays = estimateRunwayDays(dosesRemaining, medication.schedules);
 
   return (

src/components/medications/sections/inventory-section.tsx

@@ -76,7 +76,7 @@ import {
   apiPost,
   apiPut,
 } from "@/lib/api/api-fetch";
-import { summariseSupply } from "@/lib/medications/inventory/summary";
+import type { SupplySummary } from "@/lib/medications/inventory/summary";
 
 /**
  * Invalidate every read key whose payload reflects a medication's supply
@@ -127,6 +127,11 @@ interface InventoryItem {
 
 interface InventoryResponse {
   items: InventoryItem[];
+  // v1.19.0 (iOS#25) — server-authoritative supply summary. The headline
+  // figures are computed server-side via the shared `summariseSupply`
+  // helper and shipped ready; the client renders them rather than
+  // re-deriving in the browser, so web and iOS agree on the Bestand.
+  summary?: SupplySummary;
   meta?: { total: number };
 }
 
@@ -232,28 +237,19 @@ export function InventorySection({
   }
 
   const items = Array.isArray(data?.items) ? data.items : [];
-  // Available supply: ACTIVE / IN_USE containers with units left — the
-  // shared summary helper keeps this row, the Übersicht row, the list
-  // payload and the GLP-1 endpoint on one predicate. Expired stock is
-  // never available; it renders as a separate muted suffix.
-  // Dose-derived headline (floor — a partial dose is not a dose).
-  // v1.18.3 (iOS#31) — an unknown-units row (null) contributes nothing to
-  // the available-supply math; it shows "—" in its own row but cannot pad
-  // the pooled headline. Coalesce null → 0 only for the summary inputs.
-  const {
-    unitsRemaining: remainingUnits,
-    unitsTotal: totalUnits,
-    dosesRemaining: remaining,
-    dosesTotal: total,
-    expiredUnits,
-  } = summariseSupply(
-    items.map((item) => ({
-      state: item.state,
-      unitsTotal: item.unitsTotal ?? 0,
-      unitsRemaining: item.unitsRemaining ?? 0,
-    })),
-    perDose,
-  );
+  // v1.19.0 (iOS#25) — the supply headline is server-authoritative: the
+  // GET response carries a `summary` computed server-side through the
+  // shared `summariseSupply` helper (ACTIVE / IN_USE with units left;
+  // EXPIRED surfaced separately, never available; dose-derived counts
+  // floored). The client renders these ready figures so web and iOS show
+  // identical numbers. The per-item rows below still divide by `perDose`
+  // locally, which is presentation only — the canonical pool is the DTO.
+  const summary = data?.summary;
+  const remainingUnits = summary?.unitsRemaining ?? 0;
+  const totalUnits = summary?.unitsTotal ?? 0;
+  const remaining = summary?.dosesRemaining ?? 0;
+  const total = summary?.dosesTotal ?? 0;
+  const expiredUnits = summary?.expiredUnits ?? 0;
 
   const dialogs = (
     <>