feat(shared): Länderauswahl mit ISO 3166-1 Mapping und CountryPicker

Backend: Country-Record (Shared Kernel), InMemoryCountryRepository mit
~249 Ländern und DACH-Priorisierung, ListCountries-UseCase,
GET /api/countries?q= Endpoint.

Frontend: CountryPicker-Komponente mit Fuzzy-Suche, DACH-Favoriten bei
leerem Query. SupplierCreate-, CustomerCreate- und AddDeliveryAddress-
Screens verwenden jetzt den CountryPicker statt Freitext. Detail-Screens
zeigen den Ländercode in der Adressanzeige.

Closes #71

frontend/packages/api-client/src/index.ts

@@ -27,6 +27,7 @@ export { createRecipesResource } from './resources/recipes.js';
 export { createBatchesResource } from './resources/batches.js';
 export { createProductionOrdersResource } from './resources/production-orders.js';
 export { createStocksResource } from './resources/stocks.js';
+export { createCountriesResource } from './resources/countries.js';
 export {
   ApiError,
   AuthenticationError,
@@ -111,6 +112,7 @@ export type {
   ReservationDTO,
   StockBatchAllocationDTO,
   ReserveStockRequest,
+  CountryDTO,
 } from '@effigenix/types';
 
 // Resource types (runtime, stay in resource files)
@@ -141,6 +143,7 @@ export { BATCH_STATUS_LABELS } from './resources/batches.js';
 export type { ProductionOrdersResource, Priority } from './resources/production-orders.js';
 export { PRIORITY_LABELS } from './resources/production-orders.js';
 export type { StocksResource, BatchType, StockBatchStatus, StockFilter, ReferenceType, ReservationPriority } from './resources/stocks.js';
+export type { CountriesResource } from './resources/countries.js';
 export { BATCH_TYPE_LABELS, STOCK_BATCH_STATUS_LABELS, REFERENCE_TYPE_LABELS, RESERVATION_PRIORITY_LABELS } from './resources/stocks.js';
 
 import { createApiClient } from './client.js';
@@ -156,6 +159,7 @@ import { createRecipesResource } from './resources/recipes.js';
 import { createBatchesResource } from './resources/batches.js';
 import { createProductionOrdersResource } from './resources/production-orders.js';
 import { createStocksResource } from './resources/stocks.js';
+import { createCountriesResource } from './resources/countries.js';
 import type { TokenProvider } from './token-provider.js';
 import type { ApiConfig } from '@effigenix/config';
 
@@ -182,6 +186,7 @@ export function createEffigenixClient(
     batches: createBatchesResource(axiosClient),
     productionOrders: createProductionOrdersResource(axiosClient),
     stocks: createStocksResource(axiosClient),
+    countries: createCountriesResource(axiosClient),
   };
 }
 

frontend/packages/api-client/src/resources/countries.ts

@@ -0,0 +1,17 @@
+import type { AxiosInstance } from 'axios';
+import type { CountryDTO } from '@effigenix/types';
+
+export type { CountryDTO };
+
+export function createCountriesResource(client: AxiosInstance) {
+  return {
+    async search(query?: string): Promise<CountryDTO[]> {
+      const res = await client.get<CountryDTO[]>('/api/countries', {
+        params: query ? { q: query } : {},
+      });
+      return res.data;
+    },
+  };
+}
+
+export type CountriesResource = ReturnType<typeof createCountriesResource>;

frontend/packages/types/src/country.ts

@@ -0,0 +1,4 @@
+export interface CountryDTO {
+  code: string;
+  name: string;
+}

frontend/packages/types/src/index.ts

@@ -17,6 +17,7 @@ export * from './article';
 export * from './customer';
 export * from './inventory';
 export * from './production';
+export * from './country';
 
 // Re-export generated types for advanced usage
 export type { components, paths } from './generated/api';