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,