Add Lieferungen section with supplier CRUD and delivery create/list.

Wire /lieferung sub-nav (list, neu, lieferanten) to supplier and delivery APIs.

src/api/index.js

@@ -521,6 +521,84 @@ export const brand = {
   },
 };
 
+/**
+ * Company-scoped suppliers / Lieferanten (selectedCompanyId from session).
+ * Shape: Supplier = { id, name, createdAt, updatedAt }
+ */
+export const supplier = {
+  /** GET /api/supplier → { suppliers: Supplier[] } */
+  list() {
+    return http('/api/supplier');
+  },
+
+  /**
+   * POST /api/supplier
+   * Body: { name } — empty name ⇒ 400 Name required.
+   * → 201 { supplier: Supplier }
+   */
+  create(body) {
+    return http('/api/supplier', { method: 'POST', body });
+  },
+
+  /**
+   * PATCH /api/supplier/:id
+   * Body: { name } — empty name ⇒ 400 Name required.
+   * → 200 { supplier: Supplier }
+   */
+  update(id, body) {
+    return http(`/api/supplier/${id}`, { method: 'PATCH', body });
+  },
+
+  /** DELETE /api/supplier/:id → 204 */
+  delete(id) {
+    return http(`/api/supplier/${id}`, { method: 'DELETE' });
+  },
+};
+
+/**
+ * Company-scoped goods receipts (manifest type = delivery).
+ * DeliverySummary = { id, number, type: 'delivery', supplierId, date }
+ * DeliveryLine = { id, articleId, sku, amount, net, transactedAmount, rebate, tax, comment }
+ * Delivery = DeliverySummary & { lines: DeliveryLine[] }
+ * DeliveryLineInput = { sku, amount, net, tax, rebate?, transactedAmount?, comment? }
+ */
+export const delivery = {
+  /** GET /api/delivery → { deliveries: DeliverySummary[] } */
+  list() {
+    return http('/api/delivery');
+  },
+
+  /** GET /api/delivery/:id → { delivery: Delivery } */
+  get(id) {
+    return http(`/api/delivery/${id}`);
+  },
+
+  /**
+   * POST /api/delivery
+   * Body: { number, date, supplierId?, lines: DeliveryLineInput[] }
+   * Line requires sku, amount, net, tax. rebate→0, transactedAmount→amount.
+   * → 201 { delivery: Delivery }
+   */
+  create(body) {
+    return http('/api/delivery', { method: 'POST', body });
+  },
+
+  /**
+   * PATCH /api/delivery/:id
+   * Body: partial { number?, date?, supplierId?, lines? }.
+   * If lines present, replaces all lines; if omitted, lines unchanged.
+   * → 200 { delivery: Delivery }
+   */
+  update(id, body) {
+    return http(`/api/delivery/${id}`, { method: 'PATCH', body });
+  },
+
+  /** DELETE /api/delivery/:id → 204 */
+  delete(id) {
+    return http(`/api/delivery/${id}`, { method: 'DELETE' });
+  },
+};
+
 export const company = {
   /** GET /api/company → { companies: [...] } */
   list() {
@@ -697,6 +775,8 @@ export default {
   category,
   company,
   posterminal,
+  supplier,
+  delivery,
   thumb,
   unit,
 };