feat(backend): Inventar (Modul 24)

EquipmentModule (GET/POST /equipment, GET/PATCH /equipment/:id) fuer
Ausruestungsgegenstaende (Inventarnummer, Bezeichnung, Hersteller,
Kaufdatum, Zustand, Standort, Wartungsdatum). Neues Prisma-Modell
Equipment (Migration equipment).

ApiCore-Backend/prisma/schema.prisma

@@ -672,3 +672,29 @@ model BottlingBatch {
   @@index([honeyBatchId])
   @@index([productId])
 }
+
+// ---------------------------------------------------------------------------
+// Inventar (Abschnitt 4.22) – v1.x Modul 24
+// ---------------------------------------------------------------------------
+
+enum EquipmentCondition {
+  NEW
+  GOOD
+  WORN
+  DEFECTIVE
+}
+
+model Equipment {
+  id              String             @id @default(cuid())
+  inventoryNumber String             @unique
+  name            String
+  manufacturer    String?
+  purchaseDate    DateTime?
+  condition       EquipmentCondition @default(GOOD)
+  location        String?
+  maintenanceDate DateTime?
+  createdAt       DateTime           @default(now())
+  updatedAt       DateTime           @updatedAt
+
+  @@index([condition])
+}