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/common/EditableTable/EditableTable.tsx

@@ -12,7 +12,7 @@ import {
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
-import { Plus, Trash2, GripVertical } from 'lucide-react';
+import { Plus, Trash2 } from 'lucide-react';
 import { cn } from '@/lib/utils';
 
 export interface EditableColumn<T> {

src/components/common/NoticePopupModal/NoticePopupContainer.tsx

@@ -4,7 +4,6 @@ import { useEffect, useState } from 'react';
 import { NoticePopupModal, isPopupDismissedForToday } from './NoticePopupModal';
 import { getActivePopups } from './actions';
 import type { NoticePopupData } from './NoticePopupModal';
-import type { Popup } from '@/components/settings/PopupManagement/types';
 
 /**
  * 활성 팝업을 자동으로 가져와 순차적으로 표시하는 컨테이너

src/components/common/ParentMenuRedirect.tsx

@@ -19,7 +19,7 @@ interface ParentMenuRedirectProps {
  */
 export function ParentMenuRedirect({ parentPath, fallbackPath }: ParentMenuRedirectProps) {
   const router = useRouter();
-  const pathname = usePathname();
+  const _pathname = usePathname();
 
   useEffect(() => {
     try {

src/components/common/ScheduleCalendar/ScheduleBar.tsx

@@ -50,7 +50,7 @@ export function ScheduleBar({
   const leftPercent = (startCol / 7) * 100;
 
   // 툴팁 내용 생성
-  const tooltipContent = `${event.title}\n기간: ${event.startDate} ~ ${event.endDate}`;
+  const _tooltipContent = `${event.title}\n기간: ${event.startDate} ~ ${event.endDate}`;
 
   return (
     <TooltipProvider delayDuration={200}>

src/components/common/ScheduleCalendar/WeekView.tsx

@@ -2,7 +2,6 @@
 
 import { useMemo } from 'react';
 import { cn } from '@/components/ui/utils';
-import { DayCell } from './DayCell';
 import { ScheduleBar } from './ScheduleBar';
 import { MorePopover } from './MorePopover';
 import type { WeekViewProps } from './types';
@@ -132,7 +131,7 @@ export function WeekView({
         {/* 날짜 셀들 */}
         {weekDays.map((date, colIndex) => {
           const dayOfWeek = getDay(date);
-          const isWeekend = dayOfWeek === 0 || dayOfWeek === 6;
+          const _isWeekend = dayOfWeek === 0 || dayOfWeek === 6;
           const badge = getBadgeForDate(badges, date);
           const hiddenCount = hiddenEventCounts.get(colIndex) || 0;
           const dayEvents = getEventsForDate(events, date);