fix(medications): English tab slugs in the URL, old links still open

The medication detail tabs put German words into the address for
every language (`?tab=verlauf`, `?tab=bestand`). They are overview,
effect, schedule, supply, history, injection and advanced now. Every
old slug maps to its tab, so a bookmark, a link in an old report or a
low-stock notification sent before the change opens where it did. The
low-stock push, the list card and the efficacy summary link with the
new slugs. The slug vocabulary moves into its own module with a test.

src/__tests__/baselines/source-file-lines.json

@@ -1,7 +1,7 @@
 {
   "$comment": "Production files over 800 lines and their length. Maintained by src/__tests__/source-size-ratchet.test.ts.",
   "count": 84,
-  "total": 93880,
+  "total": 93824,
   "entries": {
     "app/medications/page-client.tsx": 839,
     "components/charts/mood-chart.tsx": 1166,
@@ -13,7 +13,7 @@
     "components/insights/health-score-card.tsx": 1023,
     "components/insights/insights-tab-strip.tsx": 1087,
     "components/measurements/measurement-form.tsx": 815,
-    "components/medications/detail/medication-detail-tabs.tsx": 1157,
+    "components/medications/detail/medication-detail-tabs.tsx": 1129,
     "components/medications/medication-table.tsx": 853,
     "components/medications/wizard/wizard-payload.ts": 1414,
     "components/mood/mood-list.tsx": 1408,

src/__tests__/baselines/source-function-lines.json

@@ -1,7 +1,7 @@
 {
   "$comment": "Production functions over 200 lines, keyed \"file :: name\", and their length. Maintained by src/__tests__/source-size-ratchet.test.ts.",
   "count": 339,
-  "total": 110080,
+  "total": 110064,
   "entries": {
     "app/achievements/page.tsx :: AchievementsPage": 206,
     "app/api/admin/backups/upload/route.ts :: apiHandler(arg)": 275,
@@ -147,10 +147,10 @@
     "components/measurement-reminders/vorsorge-section.tsx :: VorsorgeSection": 352,
     "components/measurements/measurement-form.tsx :: MeasurementForm": 496,
     "components/medications/detail/efficacy/efficacy-chart.tsx :: EfficacyChart": 361,
-    "components/medications/detail/medication-detail-tabs.tsx :: MedicationDetailTabs": 767,
+    "components/medications/detail/medication-detail-tabs.tsx :: MedicationDetailTabs": 760,
     "components/medications/dose-history-add-dialog.tsx :: LedgerAddDialog": 223,
     "components/medications/dose-strength-curve.tsx :: DoseStrengthCurve": 266,
-    "components/medications/glp1-medication-card.tsx :: Glp1MedicationCard": 405,
+    "components/medications/glp1-medication-card.tsx :: Glp1MedicationCard": 396,
     "components/medications/injection-site-picker.tsx :: InjectionSitePicker": 287,
     "components/medications/intake-history-list-v2.tsx :: IntakeHistoryListV2": 403,
     "components/medications/intake-import-dialog.tsx :: IntakeImportDialog": 208,

src/app/medications/[id]/history/page.tsx

@@ -21,7 +21,7 @@ export default function IntakeHistoryRedirectPage({
   const router = useRouter();
 
   useEffect(() => {
-    router.replace(`/medications/${id}?tab=verlauf`);
+    router.replace(`/medications/${id}?tab=history`);
   }, [id, router]);
 
   return (

src/app/medications/page-client.tsx

@@ -435,7 +435,7 @@ export default function MedicationsPageClient() {
 
   function openHistory(med: Medication) {
     seedDetail(med);
-    router.push(`/medications/${med.id}?tab=verlauf`);
+    router.push(`/medications/${med.id}?tab=history`);
   }
 
   function closeDialog() {

src/components/day/__tests__/day-view.test.tsx

@@ -38,7 +38,7 @@ const DAY: DayResponse = {
       until: "2026-03-31",
       dayIndex: 64,
       dayCount: 151,
-      href: "/medications/m1?tab=verlauf",
+      href: "/medications/m1?tab=history",
     },
   ],
   values: [

src/components/insights/medication-efficacy-summary.tsx

@@ -114,7 +114,7 @@ export function MedicationEfficacySummary({
                   </div>
                   <InlineAction asChild className="shrink-0">
                     <Link
-                      href={`/medications/${med.id}?tab=wirkung`}
+                      href={`/medications/${med.id}?tab=effect`}
                       data-slot="insights-medication-efficacy-link"
                     >
                       {t("medications.efficacy.insights.link")}

src/components/medications/__tests__/detail-page-cascade.test.tsx

@@ -111,8 +111,6 @@ describe("medication detail compliance applicability", () => {
   });
 
   it("keeps PRN compliance disabled at the query boundary", () => {
-    expect(source).toContain(
-      'enabled: activeTab === "uebersicht" && !asNeeded',
-    );
+    expect(source).toContain('enabled: activeTab === "overview" && !asNeeded');
   });
 });

src/components/medications/__tests__/medication-tab-slugs.test.ts

@@ -0,0 +1,51 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  resolveTabSlug,
+  TAB_SLUGS,
+} from "@/components/medications/detail/tab-slugs";
+
+/**
+ * The medication tabs carried German slugs in every language
+ * (`?tab=verlauf`). They are English now, and every old link (a bookmark,
+ * a report, a low-stock notification sent before the change) still lands on
+ * the tab it named.
+ */
+describe("medication tab slugs", () => {
+  const all = [...TAB_SLUGS];
+
+  it("opens a tab by its own slug", () => {
+    expect(resolveTabSlug("history", all)).toBe("history");
+    expect(resolveTabSlug("supply", all)).toBe("supply");
+  });
+
+  it.each([
+    ["uebersicht", "overview"],
+    ["wirkung", "effect"],
+    ["zeitplan", "schedule"],
+    ["bestand", "supply"],
+    ["verlauf", "history"],
+    ["injektion", "injection"],
+    ["erweitert", "advanced"],
+    ["erinnerung", "schedule"],
+    ["api", "advanced"],
+  ] as const)("sends the old ?tab=%s to %s", (legacy, tab) => {
+    expect(resolveTabSlug(legacy, all)).toBe(tab);
+  });
+
+  it("falls back to the overview for a missing, unknown or unavailable tab", () => {
+    expect(resolveTabSlug(null, all)).toBe("overview");
+    expect(resolveTabSlug("constructor", all)).toBe("overview");
+    expect(resolveTabSlug("nope", all)).toBe("overview");
+    expect(
+      resolveTabSlug(
+        "injektion",
+        all.filter((tab) => tab !== "injection"),
+      ),
+    ).toBe("overview");
+  });
+
+  it("keeps every slug URL-safe ASCII", () => {
+    for (const slug of TAB_SLUGS) expect(slug).toMatch(/^[a-z]+$/);
+  });
+});

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

@@ -6,12 +6,12 @@
  * Promotes the detail page from a read-only history view to the
  * canonical home for ONE medication. The modal `<AdvancedSettingsSheet>`
  * is dissolved into the Erweitert tab (no more five-card stack in a
- * sheet) and the separate `/history` route folds into the Verlauf tab
- * (the route now redirects to `?tab=verlauf`).
+ * sheet) and the separate `/history` route folds into the history tab
+ * (the route now redirects to `?tab=history`).
  *
  * Tab state lives in the URL (`?tab=<slug>`), so a tab is deep-linkable,
  * survives reload, and is reachable from the medications-list card kebab
- * (History→verlauf). The kebab's Edit arrives as `?edit=1`, which opens
+ * (History). The kebab's Edit arrives as `?edit=1`, which opens
  * the wizard in edit mode on top of the landing tab. Slugs are ASCII /
  * locale-independent; the visible labels are i18n.
  *
@@ -20,7 +20,7 @@
  * switch + the reminder grace), and Übersicht grew from a lone
  * compliance bar into the status landing surface (next due dose,
  * reminder state, supply runway — each with a jump link into its owner
- * tab). Stale `?tab=erinnerung` deep-links land on Zeitplan.
+ * tab). Stale `?tab=erinnerung` deep-links land on the schedule tab.
  *
  * Only the active tab body mounts (Radix `Tabs` default) so inactive tabs
  * do not fetch. The hero stays above the tabs as the always-visible
@@ -106,6 +106,12 @@ import { MedicationRelatedSection } from "@/components/medications/detail/medica
 import type { RelatedLink } from "@/lib/links/related";
 import { InlineAction } from "@/components/ui/inline-action";
 import { EmptyState } from "@/components/ui/empty-state";
+import {
+  resolveTabSlug,
+  TAB_LABEL_KEYS,
+  TAB_SLUGS,
+  type TabSlug,
+} from "@/components/medications/detail/tab-slugs";
 
 // v1.15.20 — Recharts stays out of the detail page's initial bundle:
 // both chart bodies load through `next/dynamic` (client-only) with the
@@ -202,20 +208,6 @@ export interface MedicationDetailSnapshot {
   related?: RelatedLink[];
 }
 
-// Slugs are ASCII / locale-independent so the URL stays stable across
-// locales; the visible labels resolve through i18n. The list drives both
-// the tab strip render and the `?tab=` round-trip validation.
-const TAB_SLUGS = [
-  "uebersicht",
-  "wirkung",
-  "zeitplan",
-  "bestand",
-  "verlauf",
-  "injektion",
-  "erweitert",
-] as const;
-type TabSlug = (typeof TAB_SLUGS)[number];
-
 /**
  * Tabs whose entire content is owner-only work: the schedule editor and its
  * plan history, the supply ledger, the external-token row, and the advanced
@@ -225,10 +217,10 @@ type TabSlug = (typeof TAB_SLUGS)[number];
 const OWNER_ONLY_TABS: ReadonlySet<TabSlug> = new Set([
   // Schedule times are a MANAGE route, but the tab also carries the reminder
   // and notification settings, which resolve the caller.
-  "zeitplan",
+  "schedule",
   // Phase config, export and the per-medication tokens (a credential
   // surface, never delegated) resolve the caller.
-  "erweitert",
+  "advanced",
 ]);
 
 /**
@@ -237,20 +229,7 @@ const OWNER_ONLY_TABS: ReadonlySet<TabSlug> = new Set([
  * is one; the three above are not, because each mixes in a route that
  * resolves the caller and would 403 under a switch.
  */
-const MANAGE_TABS: ReadonlySet<TabSlug> = new Set(["bestand"]);
-
-/**
- * Legacy slugs that point at a dissolved tab. The Erinnerung tab folded
- * into Zeitplan in v1.15.20; old deep-links keep landing on the surface
- * that now owns the reminder controls instead of falling back to the
- * landing tab.
- */
-const LEGACY_TAB_SLUGS: Record<string, TabSlug> = {
-  erinnerung: "zeitplan",
-  // The API tab folded back into Erweitert in v1.42: two tabs for the
-  // rarely-opened owner settings made a strip that could not fit a phone.
-  api: "erweitert",
-};
+const MANAGE_TABS: ReadonlySet<TabSlug> = new Set(["supply"]);
 
 function snapshotToWizardPayload(
   med: MedicationDetailSnapshot,
@@ -364,26 +343,26 @@ export function MedicationDetailTabs({
 
   // Only the active tab body mounts, but the tab REGISTRY must agree with
   // whatever `?tab=` carries — Injektion is absent for non-injectable
-  // medications, so a stale `?tab=injektion` deep-link falls back to the
+  // medications, so a stale `?tab=injection` deep-link falls back to the
   // landing tab instead of rendering an empty surface.
   // v1.16.11 — an as-needed medication has no schedule and never
   // reminds, so the Zeitplan tab (times editor + reminder card +
   // plan-history) does not apply and is dropped from the registry; a
-  // stale `?tab=zeitplan` deep-link falls back to the landing tab.
+  // stale `?tab=schedule` deep-link falls back to the landing tab.
   // v1.36.x — four tabs are nothing BUT owner work: the schedule editor, the
   // supply ledger, the external-token row and the advanced surface that holds
   // the wizard, the import and the destructive zone. None of it is delegated,
   // so inside somebody else's record they leave the registry entirely rather
   // than opening onto controls the server refuses — which also means a stale
-  // `?tab=erweitert` deep link lands on the landing tab, the same way an
+  // `?tab=advanced` deep link lands on the landing tab, the same way an
   // inapplicable tab already does.
   const availableTabs = useMemo<TabSlug[]>(
     () =>
       TAB_SLUGS.filter(
         (slug) =>
-          (slug !== "injektion" || isInjectable) &&
-          (slug !== "zeitplan" || !asNeeded) &&
-          (slug !== "wirkung" || hasEfficacyTarget) &&
+          (slug !== "injection" || isInjectable) &&
+          (slug !== "schedule" || !asNeeded) &&
+          (slug !== "effect" || hasEfficacyTarget) &&
           (!inSharedRecord || !OWNER_ONLY_TABS.has(slug)) &&
           (canManageMedications || !MANAGE_TABS.has(slug)),
       ),
@@ -396,14 +375,7 @@ export function MedicationDetailTabs({
     ],
   );
 
-  const requestedRaw = searchParams?.get("tab");
-  const requested = (
-    requestedRaw && requestedRaw in LEGACY_TAB_SLUGS
-      ? LEGACY_TAB_SLUGS[requestedRaw]
-      : requestedRaw
-  ) as TabSlug | null;
-  const activeTab: TabSlug =
-    requested && availableTabs.includes(requested) ? requested : "uebersicht";
+  const activeTab = resolveTabSlug(searchParams?.get("tab"), availableTabs);
 
   useEffect(() => {
     if (shouldOpenEditFromUrl) {
@@ -438,7 +410,7 @@ export function MedicationDetailTabs({
     },
     // v1.16.11 — no compliance read for an as-needed medication (the
     // section is hidden; there is no rate to fetch).
-    enabled: activeTab === "uebersicht" && !asNeeded,
+    enabled: activeTab === "overview" && !asNeeded,
     staleTime: 30_000,
   });
 
@@ -468,7 +440,7 @@ export function MedicationDetailTabs({
         return null;
       }
     },
-    enabled: activeTab === "uebersicht",
+    enabled: activeTab === "overview",
     staleTime: 30_000,
   });
 
@@ -549,7 +521,7 @@ export function MedicationDetailTabs({
               value={slug}
               data-slot={`medication-tab-${slug}`}
             >
-              {t(`medications.detail.tabs.${slug}`)}
+              {t(TAB_LABEL_KEYS[slug])}
             </TabsTrigger>
           ))}
         </TabsList>
@@ -558,7 +530,7 @@ export function MedicationDetailTabs({
             reminder state and supply runway (each with a jump link into
             its owner tab), then the compliance readout. All values come
             from data the page already holds — no new endpoints. */}
-        <TabsContent value="uebersicht" className="space-y-6 pt-2">
+        <TabsContent value="overview" className="space-y-6 pt-2">
           <MedicationDetailSection
             titleId="medication-uebersicht-status-heading"
             title={t("medications.detail.uebersicht.statusTitle")}
@@ -583,7 +555,7 @@ export function MedicationDetailTabs({
                     ? t("medications.detail.uebersicht.jumpToVerlauf")
                     : t("medications.detail.uebersicht.jumpToZeitplan")
                 }
-                onJump={() => onTabChange(asNeeded ? "verlauf" : "zeitplan")}
+                onJump={() => onTabChange(asNeeded ? "history" : "schedule")}
                 dataSlot="uebersicht-next-dose"
               />
               {/* v1.16.11 — as-needed never reminds; the row would only
@@ -597,7 +569,7 @@ export function MedicationDetailTabs({
                       : t("medications.detail.uebersicht.reminderOff")
                   }
                   jumpLabel={t("medications.detail.uebersicht.jumpToZeitplan")}
-                  onJump={() => onTabChange("zeitplan")}
+                  onJump={() => onTabChange("schedule")}
                   dataSlot="uebersicht-reminder"
                 />
               )}
@@ -639,7 +611,7 @@ export function MedicationDetailTabs({
                     </>
                   }
                   jumpLabel={t("medications.detail.uebersicht.jumpToBestand")}
-                  onJump={() => onTabChange("bestand")}
+                  onJump={() => onTabChange("supply")}
                   dataSlot="uebersicht-supply"
                 />
               )}
@@ -692,10 +664,10 @@ export function MedicationDetailTabs({
             with a before/after comparison + adherence lane. Strictly
             descriptive; hidden for one-shot + no-target medications. */}
         {hasEfficacyTarget && (
-          <TabsContent value="wirkung" className="space-y-6 pt-2">
+          <TabsContent value="effect" className="space-y-6 pt-2">
             <EfficacyTab
               medicationId={id}
-              active={activeTab === "wirkung"}
+              active={activeTab === "effect"}
               isGlp1={isGlp1}
               medicationName={medication.name}
               medicationDose={medication.dose}
@@ -708,7 +680,7 @@ export function MedicationDetailTabs({
             notifications switch + the reminder grace, folded in from the
             dissolved Erinnerung tab). Cadence-kind stays structural (the
             hero's "Vollständig bearbeiten"). */}
-        <TabsContent value="zeitplan" className="space-y-6 pt-2">
+        <TabsContent value="schedule" className="space-y-6 pt-2">
           {/* v1.39.1 (#1033) — the intake-tracking switch leads the tab:
               it decides whether the times below are a dose plan or a
               record. */}
@@ -827,7 +799,7 @@ export function MedicationDetailTabs({
         </TabsContent>
 
         {/* BESTAND — inventory readout + register / correct flows. */}
-        <TabsContent value="bestand" className="space-y-4 pt-2">
+        <TabsContent value="supply" className="space-y-4 pt-2">
           <InventorySection
             medicationId={id}
             dosesPerUnit={medication.dosesPerUnit}
@@ -841,7 +813,7 @@ export function MedicationDetailTabs({
             optimistic recompute, edit/add (incl. the late-take "diesem
             Slot zuordnen?" nudge). CSV import lives under Erweitert →
             Daten (the DataPortabilityRow), not in this header. */}
-        <TabsContent value="verlauf" className="space-y-6 pt-2">
+        <TabsContent value="history" className="space-y-6 pt-2">
           <div className="flex justify-end">
             <Segmented
               mode="toggle"
@@ -887,7 +859,7 @@ export function MedicationDetailTabs({
             side-effect log; the body-map + adherence detail land next
             wave. */}
         {isInjectable && (
-          <TabsContent value="injektion" className="space-y-6 pt-2">
+          <TabsContent value="injection" className="space-y-6 pt-2">
             {/* Dose-escalation plan: completed + planned titration steps
                 with a "you are here" marker. Renders for every injectable
                 route (not GLP-1-only) since titration is a property of the
@@ -916,7 +888,7 @@ export function MedicationDetailTabs({
         {/* ERWEITERT — Lifecycle → Daten → external API → Gefahrenzone.
             The API tab folded back in here (v1.42); its group stays
             collapsed like the other two, and the danger zone stays last. */}
-        <TabsContent value="erweitert" className="space-y-4 pt-2">
+        <TabsContent value="advanced" className="space-y-4 pt-2">
           <SettingsGroup
             label={t("medications.detail.erweitert.group.lifecycle")}
             dataSlot="erweitert-group-lifecycle"

src/components/medications/detail/tab-slugs.ts

@@ -0,0 +1,58 @@
+/**
+ * The medication detail page's tab slugs, and what an old `?tab=` value maps
+ * to. Slugs are ASCII and the same in every locale so a link stays stable;
+ * the visible labels resolve through i18n.
+ */
+export const TAB_SLUGS = [
+  "overview",
+  "effect",
+  "schedule",
+  "supply",
+  "history",
+  "injection",
+  "advanced",
+] as const;
+export type TabSlug = (typeof TAB_SLUGS)[number];
+
+/**
+ * Slugs an old link may still carry. The tabs used to have German slugs in
+ * every language; links in old reports, notifications and bookmarks keep
+ * landing on the same tab. The Erinnerung tab folded into the schedule tab,
+ * and the API tab into the advanced one.
+ */
+export const LEGACY_TAB_SLUGS: Record<string, TabSlug> = {
+  uebersicht: "overview",
+  wirkung: "effect",
+  zeitplan: "schedule",
+  bestand: "supply",
+  verlauf: "history",
+  injektion: "injection",
+  erweitert: "advanced",
+  erinnerung: "schedule",
+  api: "advanced",
+};
+
+/** The tab labels; the message keys predate the English slugs. */
+export const TAB_LABEL_KEYS: Record<TabSlug, string> = {
+  overview: "medications.detail.tabs.uebersicht",
+  effect: "medications.detail.tabs.wirkung",
+  schedule: "medications.detail.tabs.zeitplan",
+  supply: "medications.detail.tabs.bestand",
+  history: "medications.detail.tabs.verlauf",
+  injection: "medications.detail.tabs.injektion",
+  advanced: "medications.detail.tabs.erweitert",
+};
+
+/**
+ * The tab a `?tab=` value opens: its own slug, or the one an old slug maps
+ * to, when that tab is available for this medication; the overview
+ * otherwise.
+ */
+export function resolveTabSlug(
+  raw: string | null | undefined,
+  available: readonly TabSlug[],
+): TabSlug {
+  const slug =
+    raw && Object.hasOwn(LEGACY_TAB_SLUGS, raw) ? LEGACY_TAB_SLUGS[raw] : raw;
+  return available.find((tab) => tab === slug) ?? "overview";
+}

src/components/medications/glp1-medication-card.tsx

@@ -174,7 +174,7 @@ interface Glp1MedicationCardProps {
   onEdit: (med: Glp1Medication) => void;
   /**
    * v1.15.18 — navigates to the medication detail page's Verlauf tab
-   * (`/medications/{id}?tab=verlauf`), mirroring the generic medication
+   * (`/medications/{id}?tab=history`), mirroring the generic medication
    * card. The parent owns the navigation.
    */
   onOpenHistory: (med: Glp1Medication) => void;

src/components/medications/medication-card.tsx

@@ -147,7 +147,7 @@ interface MedicationCardProps {
   onEdit: (med: Medication) => void;
   /**
    * v1.15.18 — navigates to the medication detail page's Verlauf tab
-   * (`/medications/{id}?tab=verlauf`). The parent owns the navigation.
+   * (`/medications/{id}?tab=history`). The parent owns the navigation.
    */
   onOpenHistory: (med: Medication) => void;
   /**

src/lib/jobs/__tests__/medication-low-stock.test.ts

@@ -310,7 +310,7 @@ describe("runMedicationLowStockTick", () => {
           thresholdDays: 7,
           unitsRemaining: 5,
           // Deep link lands on the detail page's Bestand (supply) tab.
-          url: "/medications/med-1?tab=bestand",
+          url: "/medications/med-1?tab=supply",
         }),
       }),
     );

src/lib/jobs/medication-low-stock.ts

@@ -621,7 +621,7 @@ export async function runMedicationLowStockTick(
                 // the service-worker payload's click target. Lands on
                 // the detail page's Bestand (supply) tab, the surface
                 // the alert is about.
-                url: `/medications/${med.id}?tab=bestand`,
+                url: `/medications/${med.id}?tab=supply`,
               },
             });
             if (!outcome.dispatched) {

src/lib/notifications/senders/apns.ts

@@ -1031,7 +1031,7 @@ const IOS_METADATA_ALLOWLIST = new Set([
   "phase",
   "date",
   // v1.16.11 — MEDICATION_LOW_STOCK deep link + context: the in-app
-  // path the push should open (`/medications/{id}?tab=bestand`) plus
+  // path the push should open (`/medications/{id}?tab=supply`) plus
   // the runway / threshold figures the iOS handler can surface.
   "url",
   "runwayDays",