feat: ESLint 정리 및 전체 코드 품질 개선

- eslint.config.mjs 규칙 강화 및 정리
- 전역 unused import/변수 제거 (312개 파일)
- next.config.ts, middleware, proxy route 개선
- CopyableCell molecule 추가
- 회계/결재/HR/생산/건설/품질/영업 등 전 도메인 lint 정리
- IntegratedListTemplateV2, DataTable, MobileCard 등 공통 컴포넌트 개선
- execute-server-action 에러 핸들링 보강

src/components/settings/AccountManagement/index.tsx

@@ -40,7 +40,7 @@ import {
   type StatCard,
 } from '@/components/templates/UniversalListPage';
 import { ListMobileCard, InfoField } from '@/components/organisms/MobileCard';
-import type { Account, AccountCategory } from './types';
+import type { Account } from './types';
 import {
   BANK_LABELS,
   ACCOUNT_CATEGORY_LABELS,
@@ -215,11 +215,11 @@ export function AccountManagement() {
       // 테이블 컬럼
       columns: [
         { key: 'no', label: 'No.', className: 'text-center w-[60px]' },
-        { key: 'category', label: '구분', className: 'min-w-[80px]' },
-        { key: 'accountType', label: '유형', className: 'min-w-[80px]' },
-        { key: 'institution', label: '금융기관', className: 'min-w-[100px]' },
-        { key: 'accountNumber', label: '계좌번호', className: 'min-w-[160px]' },
-        { key: 'accountName', label: '계좌명', className: 'min-w-[120px]' },
+        { key: 'category', label: '구분', className: 'min-w-[80px]', copyable: true },
+        { key: 'accountType', label: '유형', className: 'min-w-[80px]', copyable: true },
+        { key: 'institution', label: '금융기관', className: 'min-w-[100px]', copyable: true },
+        { key: 'accountNumber', label: '계좌번호', className: 'min-w-[160px]', copyable: true },
+        { key: 'accountName', label: '계좌명', className: 'min-w-[120px]', copyable: true },
         { key: 'status', label: '상태', className: 'min-w-[70px]' },
       ],
 
@@ -279,7 +279,7 @@ export function AccountManagement() {
         item: Account,
         _index: number,
         globalIndex: number,
-        handlers: SelectionHandlers & RowClickHandlers<Account>
+        _handlers: SelectionHandlers & RowClickHandlers<Account>
       ) => {
         return (
           <TableRow
@@ -321,8 +321,8 @@ export function AccountManagement() {
       renderMobileCard: (
         item: Account,
         _index: number,
-        globalIndex: number,
-        handlers: SelectionHandlers & RowClickHandlers<Account>
+        _globalIndex: number,
+        _handlers: SelectionHandlers & RowClickHandlers<Account>
       ) => {
         return (
           <ListMobileCard