feat(medications): once-weekly cadence preset for GLP1 category

Phase 3 of W4d GLP-1 full integration. The form gains a small
"Treatment class" selector (GENERIC | GLP-1 injection) sitting under
the existing clinical-category dropdown. Picking GLP-1 reveals two
helpers that stay hidden for every other medication:

- "Once weekly on …" preset — a single-tap weekday row that writes
  daysOfWeek=[N] + intervalWeeks=1 into the first schedule and reveals
  the advanced block so the user can still tune the window. The last
  weekday picked persists in localStorage so a follow-up med starts on
  the same day.
- "Doses per pen / vial" optional input that powers the inventory math
  (Mounjaro KwikPen = 4, Ozempic 0.25/0.5 mg = 4, Wegovy single-dose
  pen = 1). Leaving it blank keeps inventory tracking off.

The wire schema gains optional `treatmentClass` and `dosesPerUnit`
fields. Both default sensibly (GENERIC + null) so the v1.4.24 client
keeps working untouched.

Marc directive 2026-05-14: GLP-1 must integrate "harmonisch", not
crowd the form. The new affordances live behind the treatment-class
toggle — for every other med the form is byte-identical to v1.4.24.

src/app/api/medications/[id]/route.ts

@@ -71,8 +71,16 @@ export const PUT = apiHandler(
       return apiError(parsed.error.issues[0].message, 422);
     }
 
-    const { name, dose, category, active, notificationsEnabled, schedules } =
-      parsed.data;
+    const {
+      name,
+      dose,
+      category,
+      treatmentClass,
+      dosesPerUnit,
+      active,
+      notificationsEnabled,
+      schedules,
+    } = parsed.data;
 
     const pausedAtPatch =
       active === undefined
@@ -93,6 +101,8 @@ export const PUT = apiHandler(
     const baseUpdateData = {
       ...(name !== undefined && { name }),
       ...(dose !== undefined && { dose }),
+      ...(treatmentClass !== undefined && { treatmentClass }),
+      ...(dosesPerUnit !== undefined && { dosesPerUnit }),
       ...(active !== undefined && { active }),
       ...(notificationsEnabled !== undefined && { notificationsEnabled }),
       ...(schedules && {

src/app/api/medications/route.ts

@@ -83,6 +83,11 @@ export const GET = apiHandler(async () => {
   return apiSuccess(
     medications.map((m) => ({
       ...m,
+      // v1.4.25 W4d — `category` is the existing clinical taxonomy
+      // (BLOOD_PRESSURE / VITAMIN / ...) from the side-table; the
+      // Prisma model has its own `treatmentClass` (GENERIC | GLP1) that
+      // spreads through `...m` and unlocks the GLP-1 surfaces. Two
+      // orthogonal concepts, both exposed.
       category: categoryMap[m.id] ?? "OTHER",
       lastTakenAt: lastTakenAtByMedicationId[m.id] ?? null,
       todayEventCount: todayEventCountByMedId[m.id] ?? 0,
@@ -101,13 +106,18 @@ export const POST = apiHandler(async (request: NextRequest) => {
     return apiError(parsed.error.issues[0].message, 422);
   }
 
-  const { name, dose, category, schedules } = parsed.data;
+  const { name, dose, category, treatmentClass, dosesPerUnit, schedules } =
+    parsed.data;
 
   const medication = await prisma.medication.create({
     data: {
       userId: user.id,
       name,
       dose,
+      // v1.4.25 W4d — treatmentClass + dosesPerUnit are optional in the
+      // wire schema; Prisma fills the default GENERIC when omitted.
+      ...(treatmentClass !== undefined && { treatmentClass }),
+      ...(dosesPerUnit !== undefined && { dosesPerUnit }),
       schedules: {
         create: schedules.map((s) => ({
           windowStart: s.windowStart,

src/app/medications/page.tsx

@@ -56,6 +56,10 @@ interface Medication {
   name: string;
   dose: string;
   category: string;
+  /** v1.4.25 W4d — Prisma treatment class (GENERIC | GLP1). */
+  treatmentClass?: string;
+  /** v1.4.25 W4d — doses per pen/vial for inventory math. */
+  dosesPerUnit?: number | null;
   active: boolean;
   notificationsEnabled: boolean;
   pausedAt: string | null;
@@ -253,6 +257,12 @@ export default function MedicationsPage() {
                     name: editingMed.name,
                     dose: editingMed.dose,
                     category: editingMed.category,
+                    // v1.4.25 W4d — pass through the Prisma treatment-class
+                    // discriminator and the optional dosesPerUnit so the
+                    // form preselects the GLP-1 surfaces correctly when
+                    // editing an existing GLP-1 row.
+                    treatmentClass: editingMed.treatmentClass,
+                    dosesPerUnit: editingMed.dosesPerUnit ?? null,
                     active: editingMed.active,
                     notificationsEnabled: editingMed.notificationsEnabled,
                     schedules: editingMed.schedules.map((s) => ({

src/components/medications/medication-form.tsx

@@ -168,6 +168,10 @@ interface MedicationFormProps {
     name: string;
     dose: string;
     category: string;
+    /** v1.4.25 W4d — Prisma treatment class. Defaults to GENERIC. */
+    treatmentClass?: string;
+    /** v1.4.25 W4d — only relevant for inventory-tracked meds. */
+    dosesPerUnit?: number | null;
     active: boolean;
     notificationsEnabled?: boolean;
     schedules: Array<{
@@ -257,6 +261,16 @@ export function MedicationForm({
   const [doseUnit, setDoseUnit] = useState(initialDose.unit);
 
   const [category, setCategory] = useState(initial?.category ?? "OTHER");
+  // v1.4.25 W4d — treatment class. GLP1 unlocks the weekly-cadence
+  // preset below and the GLP-1 medication-card variant on the medications
+  // page. The default GENERIC keeps every existing medication rendering
+  // exactly as before.
+  const [treatmentClass, setTreatmentClass] = useState(
+    initial?.treatmentClass ?? "GENERIC",
+  );
+  const [dosesPerUnit, setDosesPerUnit] = useState<string>(
+    initial?.dosesPerUnit ? String(initial.dosesPerUnit) : "",
+  );
   const [active, setActive] = useState(initial?.active ?? true);
   const [notificationsEnabled, setNotificationsEnabled] = useState(
     initial?.notificationsEnabled ?? true,
@@ -341,12 +355,58 @@ export function MedicationForm({
     setDoseAmount("");
     setDoseUnit("");
     setCategory("OTHER");
+    setTreatmentClass("GENERIC");
+    setDosesPerUnit("");
     setActive(true);
     setNotificationsEnabled(true);
     setSchedules([{ ...DEFAULT_SCHEDULE }]);
     setError(null);
   }
 
+  /**
+   * v1.4.25 W4d — "Once weekly on …" preset. Marc directive
+   * 2026-05-14: GLP-1 receptor agonists are weekly meds, and the
+   * existing form buries that behind two advanced toggles. The preset
+   * collapses the picker to a single weekday button row that writes
+   * MedicationSchedule.daysOfWeek correctly and remembers the choice
+   * locally so the next weekly med starts on the same weekday.
+   *
+   * Persisted to localStorage as a one-row preference so the convenience
+   * survives across sessions — non-invasive (key is namespaced) and
+   * web-only (the iOS surface uses its own picker).
+   */
+  function applyWeeklyPreset(weekday: number) {
+    try {
+      localStorage.setItem("medication-form:last-weekly-weekday", String(weekday));
+    } catch {
+      /* private mode — silent */
+    }
+    setSchedules((prev) =>
+      sortSchedules(
+        prev.map((s, i) =>
+          i === 0
+            ? {
+                ...s,
+                daysOfWeek: [weekday],
+                intervalWeeks: 1,
+                showAdvanced: true,
+              }
+            : s,
+        ),
+      ),
+    );
+  }
+
+  function readLastWeeklyWeekday(): number {
+    try {
+      const raw = localStorage.getItem("medication-form:last-weekly-weekday");
+      const n = raw === null ? NaN : Number(raw);
+      return Number.isInteger(n) && n >= 0 && n <= 6 ? n : 3; // Wednesday default
+    } catch {
+      return 3;
+    }
+  }
+
   async function handleSubmit(e: React.FormEvent) {
     e.preventDefault();
     setError(null);
@@ -363,6 +423,12 @@ export function MedicationForm({
           name,
           dose,
           category,
+          treatmentClass,
+          ...(dosesPerUnit
+            ? { dosesPerUnit: Number(dosesPerUnit) }
+            : isEdit
+              ? { dosesPerUnit: null }
+              : {}),
           ...(isEdit
             ? {
                 active,
@@ -504,6 +570,33 @@ export function MedicationForm({
         </Select>
       </div>
 
+      {/* v1.4.25 W4d — treatment-class selector. Surfaces the GLP-1
+          option without crowding the existing clinical-category
+          dropdown (those are orthogonal taxonomies). GENERIC keeps the
+          form rendering exactly as v1.4.24; GLP1 opens the
+          weekly-cadence preset + pen-inventory inputs below. */}
+      <div className="space-y-1.5">
+        <Label htmlFor="med-treatment-class">
+          {t("medications.formTreatmentClass")}
+        </Label>
+        <Select value={treatmentClass} onValueChange={setTreatmentClass}>
+          <SelectTrigger id="med-treatment-class" className="w-full">
+            <SelectValue />
+          </SelectTrigger>
+          <SelectContent>
+            <SelectItem value="GENERIC">
+              {t("medications.treatmentClassGeneric")}
+            </SelectItem>
+            <SelectItem value="GLP1">
+              {t("medications.treatmentClassGlp1")}
+            </SelectItem>
+          </SelectContent>
+        </Select>
+        <p className="text-muted-foreground text-xs leading-4">
+          {t("medications.formTreatmentClassHelp")}
+        </p>
+      </div>
+
       <div className="grid grid-cols-2 gap-3">
         <div className="space-y-1.5">
           <Label htmlFor="med-dose-amount">{t("medications.formDose")}</Label>
@@ -537,6 +630,75 @@ export function MedicationForm({
         ))}
       </datalist>
 
+      {treatmentClass === "GLP1" && (
+        <>
+          {/* v1.4.25 W4d — once-weekly preset. One tap on a weekday
+              writes daysOfWeek=[N] + intervalWeeks=1 into the first
+              schedule and reveals the advanced section so the user can
+              still tune the window. Persists the last pick across
+              sessions for convenience. */}
+          <div className="border-border/70 bg-card/60 space-y-2.5 rounded-xl border p-3.5">
+            <div className="space-y-1">
+              <Label className="text-sm leading-none">
+                {t("medications.glp1WeeklyPresetTitle")}
+              </Label>
+              <p className="text-muted-foreground text-xs leading-4">
+                {t("medications.glp1WeeklyPresetHelp")}
+              </p>
+            </div>
+            <div className="flex w-full gap-1">
+              {getDayLabelsShort(t).map((label, dayIndex) => {
+                const isSelected =
+                  schedules[0]?.daysOfWeek.length === 1 &&
+                  schedules[0]?.daysOfWeek[0] === dayIndex;
+                return (
+                  <button
+                    key={dayIndex}
+                    type="button"
+                    onClick={() => applyWeeklyPreset(dayIndex)}
+                    className={`h-9 flex-1 rounded-md border text-xs font-medium transition-colors ${
+                      isSelected
+                        ? "border-primary bg-primary text-primary-foreground"
+                        : "border-border/70 bg-muted text-foreground/75 hover:bg-accent hover:text-foreground"
+                    }`}
+                    aria-pressed={isSelected}
+                  >
+                    {label}
+                  </button>
+                );
+              })}
+            </div>
+            {!schedules.some((s) => s.daysOfWeek.length === 1) && (
+              <button
+                type="button"
+                onClick={() => applyWeeklyPreset(readLastWeeklyWeekday())}
+                className="text-primary text-xs underline-offset-2 hover:underline"
+              >
+                {t("medications.glp1WeeklyPresetSuggest")}
+              </button>
+            )}
+          </div>
+          <div className="space-y-1.5">
+            <Label htmlFor="med-doses-per-unit">
+              {t("medications.glp1DosesPerUnit")}
+            </Label>
+            <Input
+              id="med-doses-per-unit"
+              type="number"
+              inputMode="numeric"
+              min={1}
+              max={100}
+              value={dosesPerUnit}
+              onChange={(e) => setDosesPerUnit(e.target.value)}
+              placeholder={t("medications.glp1DosesPerUnitPlaceholder")}
+            />
+            <p className="text-muted-foreground text-xs leading-4">
+              {t("medications.glp1DosesPerUnitHelp")}
+            </p>
+          </div>
+        </>
+      )}
+
       <div className="space-y-2">
         <div className="flex h-8 items-center justify-between">
           <Label className="text-sm leading-none">

src/lib/validations/medication.ts

@@ -15,6 +15,18 @@ export const MEDICATION_CATEGORY_VALUES = [
   "OTHER",
 ] as const;
 
+/**
+ * v1.4.25 W4d — Prisma-level treatment class. Orthogonal to
+ * `MEDICATION_CATEGORY_VALUES` (the clinical taxonomy that lives in the
+ * `medication_categories` side-table). GLP1 turns on the GLP-1
+ * specialist surfaces — injection-site picker, titration history, pen
+ * inventory, GLP-1-aware Coach replies. Future treatment classes drop
+ * into this list (INSULIN, BIOLOGIC, FERTILITY, …).
+ */
+export const MEDICATION_TREATMENT_CLASS_VALUES = ["GENERIC", "GLP1"] as const;
+export type MedicationTreatmentClass =
+  (typeof MEDICATION_TREATMENT_CLASS_VALUES)[number];
+
 export const scheduleSchema = z.object({
   windowStart: z.string().regex(timeRegex, "Format: HH:mm"),
   windowEnd: z.string().regex(timeRegex, "Format: HH:mm"),
@@ -28,6 +40,10 @@ export const createMedicationSchema = z.object({
   name: z.string().min(1).max(100),
   dose: z.string().min(1).max(50),
   category: z.enum(MEDICATION_CATEGORY_VALUES).optional(),
+  /** v1.4.25 W4d — treatment-class discriminator (GENERIC | GLP1). */
+  treatmentClass: z.enum(MEDICATION_TREATMENT_CLASS_VALUES).optional(),
+  /** v1.4.25 W4d — doses per pen/vial for inventory tracking. */
+  dosesPerUnit: z.number().int().min(1).max(100).optional(),
   schedules: z.array(scheduleSchema).min(1, "Mindestens ein Zeitfenster"),
 });
 
@@ -35,6 +51,8 @@ export const updateMedicationSchema = z.object({
   name: z.string().min(1).max(100).optional(),
   dose: z.string().min(1).max(50).optional(),
   category: z.enum(MEDICATION_CATEGORY_VALUES).optional(),
+  treatmentClass: z.enum(MEDICATION_TREATMENT_CLASS_VALUES).optional(),
+  dosesPerUnit: z.number().int().min(1).max(100).nullable().optional(),
   active: z.boolean().optional(),
   notificationsEnabled: z.boolean().optional(),
   schedules: z.array(scheduleSchema).optional(),