refactor(WEB): API 유틸 분리, 불필요 코드 정리 및 프로젝트 규칙 업데이트

- executePaginatedAction, buildApiUrl 유틸 모듈 분리
- QuoteCalculationReport, demoStore, export.ts 불필요 코드 삭제
- CLAUDE.md에 Zod 스키마 검증 및 Server Action 공통 유틸 규칙 추가
- package.json 의존성 업데이트

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

src/stores/demoStore.ts

@@ -1,39 +0,0 @@
-import { create } from 'zustand';
-import { persist } from 'zustand/middleware';
-
-export type UserRole = 'SystemAdmin' | 'Manager' | 'User' | 'Guest';
-
-interface DemoState {
-  userRole: UserRole;
-  companyName: string;
-  userName: string;
-  setUserRole: (role: UserRole) => void;
-  setCompanyName: (name: string) => void;
-  setUserName: (name: string) => void;
-  resetDemo: () => void;
-}
-
-const DEFAULT_STATE = {
-  userRole: 'Manager' as UserRole,
-  companyName: 'SAM 데모 회사',
-  userName: '홍길동',
-};
-
-export const useDemoStore = create<DemoState>()(
-  persist(
-    (set) => ({
-      ...DEFAULT_STATE,
-
-      setUserRole: (role: UserRole) => set({ userRole: role }),
-
-      setCompanyName: (name: string) => set({ companyName: name }),
-
-      setUserName: (name: string) => set({ userName: name }),
-
-      resetDemo: () => set(DEFAULT_STATE),
-    }),
-    {
-      name: 'sam-demo',
-    }
-  )
-);