refactor(WEB): SearchableSelectionModal 공통화 및 actions lookup 통합

- SearchableSelectionModal<T> 제네릭 컴포넌트 추출 (organisms)
- 검색 모달 5개 리팩토링: SupplierSearch, QuotationSelect, SalesOrderSelect, OrderSelect, ItemSearch
- shared-lookups API 유틸 추가 (거래처/품목/수주 등 공통 조회)
- create-crud-service 확장 (lookup, search 메서드)
- actions.ts 20+개 파일 lookup 패턴 통일
- 공통 페이지 패턴 가이드 문서 추가
- CLAUDE.md Common Component Usage Rules 추가

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/accounting/PurchaseManagement/actions.ts

@@ -15,6 +15,8 @@
 
 import { isNextRedirectError } from '@/lib/utils/redirect-error';
 import { executeServerAction, type ActionResult } from '@/lib/api/execute-server-action';
+import type { PaginatedApiResponse } from '@/lib/api/types';
+import { fetchVendorOptions, fetchBankAccountDetailOptions } from '@/lib/api/shared-lookups';
 import type { PurchaseRecord, PurchaseType } from './types';
 
 const API_URL = process.env.NEXT_PUBLIC_API_URL;
@@ -46,13 +48,7 @@ interface PurchaseApiData {
   updated_at?: string;
 }
 
-interface PurchaseApiPaginatedResponse {
-  data: PurchaseApiData[];
-  current_page: number;
-  last_page: number;
-  per_page: number;
-  total: number;
-}
+type PurchaseApiPaginatedResponse = PaginatedApiResponse<PurchaseApiData>;
 
 // ===== 변환 함수 =====
 
@@ -199,17 +195,7 @@ export async function getBankAccounts(): Promise<{
   data: { id: string; bankName: string; accountName: string; accountNumber: string }[];
   error?: string;
 }> {
-  const result = await executeServerAction({
-    url: `${API_URL}/api/v1/bank-accounts?per_page=100`,
-    transform: (data: { data?: { id: number; bank_name: string; account_name: string; account_number: string }[] } | { id: number; bank_name: string; account_name: string; account_number: string }[]) => {
-      type BankAccountApi = { id: number; bank_name: string; account_name: string; account_number: string };
-      const accounts: BankAccountApi[] = Array.isArray(data) ? data : (data as { data?: BankAccountApi[] })?.data || [];
-      return accounts.map(a => ({
-        id: String(a.id), bankName: a.bank_name, accountName: a.account_name, accountNumber: a.account_number,
-      }));
-    },
-    errorMessage: '은행 계좌 조회에 실패했습니다.',
-  });
+  const result = await fetchBankAccountDetailOptions();
   return { success: result.success, data: result.data || [], error: result.error };
 }
 
@@ -219,14 +205,6 @@ export async function getVendors(): Promise<{
   data: { id: string; name: string }[];
   error?: string;
 }> {
-  const result = await executeServerAction({
-    url: `${API_URL}/api/v1/clients?per_page=100`,
-    transform: (data: { data?: { id: number; name: string }[] } | { id: number; name: string }[]) => {
-      type ClientApi = { id: number; name: string };
-      const clients: ClientApi[] = Array.isArray(data) ? data : (data as { data?: ClientApi[] })?.data || [];
-      return clients.map(c => ({ id: String(c.id), name: c.name }));
-    },
-    errorMessage: '거래처 조회에 실패했습니다.',
-  });
+  const result = await fetchVendorOptions();
   return { success: result.success, data: result.data || [], error: result.error };
 }