feat(ui): stock card with withdraw and inventory count, production batches

- Bottling detail shows Abgefüllt / Webshop verkauft / Entnommen / Rest
  (negative rest flagged "Prüfen") and the full movement list; buttons
  "Entnehmen" (reason, note) and "Inventur korrigieren" (counted
  quantity, difference booked).
- Rest column in the bottling list.
- New pages for production batches (list, create, detail with the same
  stock card), sidebar entry with its own permission.
- Products get "Art" (honey vs. manufactured goods) and the webshop
  category; bottlings only offer honey articles.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Frontend/src/lib/bottling/types.ts

@@ -9,6 +9,8 @@ export interface BottlingBatch {
   bestBeforeDate: string;
   lotNumber: string;
   createdAt: string;
+  /** jarCount plus all stock movements (shop sales, withdrawals, ...). */
+  remainingCount: number;
   honeyBatch: { id: string; batchNumber: string };
   product: { id: string; name: string } | null;
 }

ApiCore-Frontend/src/lib/production-batches/api.ts

@@ -0,0 +1,36 @@
+import { apiFetch } from "@/lib/auth/api-client";
+import {
+  CreateProductionBatchInput,
+  ProductionBatch,
+  ProductionBatchFilter,
+} from "./types";
+
+export function fetchProductionBatches(
+  filter: ProductionBatchFilter = {},
+): Promise<ProductionBatch[]> {
+  const params = new URLSearchParams();
+  if (filter.productId) params.set("productId", filter.productId);
+  const query = params.toString();
+  return apiFetch<ProductionBatch[]>(
+    `/production-batches${query ? `?${query}` : ""}`,
+  );
+}
+
+export function fetchProductionBatch(id: string): Promise<ProductionBatch> {
+  return apiFetch<ProductionBatch>(`/production-batches/${id}`);
+}
+
+export function createProductionBatch(
+  input: CreateProductionBatchInput,
+): Promise<ProductionBatch> {
+  return apiFetch<ProductionBatch>("/production-batches", {
+    method: "POST",
+    body: JSON.stringify(input),
+  });
+}
+
+export function deleteProductionBatch(id: string): Promise<{ id: string }> {
+  return apiFetch<{ id: string }>(`/production-batches/${id}`, {
+    method: "DELETE",
+  });
+}

ApiCore-Frontend/src/lib/production-batches/types.ts

@@ -0,0 +1,25 @@
+export interface ProductionBatch {
+  id: string;
+  productId: string;
+  lotNumber: string;
+  date: string;
+  quantity: number;
+  bestBeforeDate: string | null;
+  notes: string | null;
+  createdAt: string;
+  remainingCount: number;
+  product: { id: string; name: string };
+}
+
+export interface CreateProductionBatchInput {
+  productId: string;
+  lotNumber: string;
+  date: string;
+  quantity: number;
+  bestBeforeDate?: string;
+  notes?: string;
+}
+
+export interface ProductionBatchFilter {
+  productId?: string;
+}

ApiCore-Frontend/src/lib/products/labels.ts

@@ -1,6 +1,18 @@
-import { ProductStatus } from "./types";
+import { ProductKind, ProductStatus, ShopCategory } from "./types";
 
 export const PRODUCT_STATUS_LABELS: Record<ProductStatus, string> = {
   ACTIVE: "Aktiv",
   DISCONTINUED: "Eingestellt",
 };
+
+export const PRODUCT_KIND_LABELS: Record<ProductKind, string> = {
+  BOTTLED_HONEY: "Honig (Bestand je Abfüllung)",
+  MANUFACTURED: "Hergestellte Ware (Bestand je Herstellungscharge)",
+};
+
+export const SHOP_CATEGORY_LABELS: Record<ShopCategory, string> = {
+  HONIG: "Honig",
+  KERZEN: "Kerzen",
+  PROPOLIS: "Propolis",
+  SONSTIGES: "Sonstiges",
+};

ApiCore-Frontend/src/lib/products/types.ts

@@ -1,5 +1,10 @@
 export type ProductStatus = "ACTIVE" | "DISCONTINUED";
 
+/** Honey: stock per bottling. Everything else: stock per production batch. */
+export type ProductKind = "BOTTLED_HONEY" | "MANUFACTURED";
+
+export type ShopCategory = "HONIG" | "KERZEN" | "PROPOLIS" | "SONSTIGES";
+
 export interface Product {
   id: string;
   name: string;
@@ -9,6 +14,8 @@ export interface Product {
   weight: number | null;
   salesUnit: string | null;
   status: ProductStatus;
+  kind: ProductKind;
+  shopCategory: ShopCategory;
   createdAt: string;
   updatedAt: string;
 }
@@ -20,6 +27,8 @@ export interface CreateProductInput {
   packagingSize?: number;
   weight?: number;
   salesUnit?: string;
+  kind?: ProductKind;
+  shopCategory?: ShopCategory;
 }
 
 export interface UpdateProductInput extends Partial<CreateProductInput> {

ApiCore-Frontend/src/lib/stock/api.ts

@@ -0,0 +1,33 @@
+import { apiFetch } from "@/lib/auth/api-client";
+import {
+  BatchStock,
+  CorrectInput,
+  StockBatchPath,
+  WithdrawInput,
+} from "./types";
+
+export function fetchStock(path: StockBatchPath, id: string): Promise<BatchStock> {
+  return apiFetch<BatchStock>(`/${path}/${id}/stock`);
+}
+
+export function withdrawStock(
+  path: StockBatchPath,
+  id: string,
+  input: WithdrawInput,
+): Promise<BatchStock> {
+  return apiFetch<BatchStock>(`/${path}/${id}/withdrawals`, {
+    method: "POST",
+    body: JSON.stringify(input),
+  });
+}
+
+export function correctStock(
+  path: StockBatchPath,
+  id: string,
+  input: CorrectInput,
+): Promise<BatchStock> {
+  return apiFetch<BatchStock>(`/${path}/${id}/corrections`, {
+    method: "POST",
+    body: JSON.stringify(input),
+  });
+}

ApiCore-Frontend/src/lib/stock/labels.ts

@@ -0,0 +1,16 @@
+import { MovementType, WithdrawalReason } from "./types";
+
+export const WITHDRAWAL_REASON_LABELS: Record<WithdrawalReason, string> = {
+  HOFLADEN: "Hofladen",
+  EIGENBEDARF: "Eigenbedarf / Geschenk",
+  BRUCH: "Bruch / Verlust",
+  PROBE: "Probe / Muster",
+  SONSTIGES: "Sonstiges",
+};
+
+export const MOVEMENT_TYPE_LABELS: Record<MovementType, string> = {
+  SHOP_SALE: "Webshop-Verkauf",
+  SHOP_RETURN: "Webshop-Rückbuchung",
+  WITHDRAWAL: "Entnahme",
+  CORRECTION: "Inventur",
+};

ApiCore-Frontend/src/lib/stock/types.ts

@@ -0,0 +1,55 @@
+/** Collection path of a batch whose stock is tracked in the movement ledger. */
+export type StockBatchPath = "bottling-batches" | "production-batches";
+
+export type WithdrawalReason =
+  | "HOFLADEN"
+  | "EIGENBEDARF"
+  | "BRUCH"
+  | "PROBE"
+  | "SONSTIGES";
+
+export type MovementType =
+  | "SHOP_SALE"
+  | "SHOP_RETURN"
+  | "WITHDRAWAL"
+  | "CORRECTION";
+
+export interface StockSummary {
+  /** Bottled or produced. */
+  initial: number;
+  /** Net shop sales (sales minus shop returns). */
+  soldInShop: number;
+  withdrawn: number;
+  /** Net inventory corrections. */
+  corrected: number;
+  remaining: number;
+}
+
+export interface StockMovement {
+  id: string;
+  type: MovementType;
+  /** Signed: negative takes stock out. */
+  quantity: number;
+  reason: WithdrawalReason | null;
+  notes: string | null;
+  apiKeyId: string | null;
+  createdAt: string;
+  user: { id: string; name: string } | null;
+  shopRequest: { externalId: string; kind: "SALE" | "RETURN" } | null;
+}
+
+export interface BatchStock {
+  summary: StockSummary;
+  movements: StockMovement[];
+}
+
+export interface WithdrawInput {
+  quantity: number;
+  reason: WithdrawalReason;
+  notes?: string;
+}
+
+export interface CorrectInput {
+  countedQuantity: number;
+  notes: string;
+}