refactor(WEB): 전체 actions.ts에 공통 API 유틸 적용

- buildApiUrl / executePaginatedAction 패턴으로 전환 (40+ actions 파일)
- 직접 URLSearchParams 조립 → buildApiUrl 유틸 사용
- 수동 페이지네이션 메타 변환 → executePaginatedAction 자동 처리
- HandoverReportDocumentModal, OrderDocumentModal 개선
- 급여관리 SalaryManagement 코드 개선
- CLAUDE.md Server Action 공통 유틸 규칙 정리

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

src/components/approval/DocumentCreate/actions.ts

@@ -14,6 +14,7 @@
 import { isNextRedirectError } from '@/lib/utils/redirect-error';
 import { cookies } from 'next/headers';
 import { executeServerAction } from '@/lib/api/execute-server-action';
+import { buildApiUrl } from '@/lib/api/query-params';
 import type {
   ExpenseEstimateItem,
   ApprovalPerson,
@@ -125,8 +126,6 @@ function transformEmployee(employee: EmployeeApiData): ApprovalPerson {
 // API 함수
 // ============================================
 
-const API_URL = process.env.NEXT_PUBLIC_API_URL;
-
 /**
  * 파일 업로드
  * @param files 업로드할 파일 배열
@@ -202,11 +201,8 @@ export async function getExpenseEstimateItems(yearMonth?: string): Promise<{
   accountBalance: number;
   finalDifference: number;
 } | null> {
-  const searchParams = new URLSearchParams();
-  if (yearMonth) searchParams.set('year_month', yearMonth);
-
   const result = await executeServerAction<ExpenseEstimateApiResponse>({
-    url: `${API_URL}/api/v1/reports/expense-estimate?${searchParams.toString()}`,
+    url: buildApiUrl('/api/v1/reports/expense-estimate', { year_month: yearMonth }),
     errorMessage: '비용견적서 조회에 실패했습니다.',
   });
   if (!result.success || !result.data) return null;
@@ -222,12 +218,8 @@ export async function getExpenseEstimateItems(yearMonth?: string): Promise<{
  * 직원 목록 조회 (결재선/참조 선택용)
  */
 export async function getEmployees(search?: string): Promise<ApprovalPerson[]> {
-  const searchParams = new URLSearchParams();
-  searchParams.set('per_page', '100');
-  if (search) searchParams.set('search', search);
-
   const result = await executeServerAction<{ data: EmployeeApiData[] }>({
-    url: `${API_URL}/api/v1/employees?${searchParams.toString()}`,
+    url: buildApiUrl('/api/v1/employees', { per_page: 100, search }),
     errorMessage: '직원 목록 조회에 실패했습니다.',
   });
   if (!result.success || !result.data?.data) return [];
@@ -276,7 +268,7 @@ export async function createApproval(formData: DocumentFormData): Promise<{
   };
 
   const result = await executeServerAction<ApprovalCreateResponse>({
-    url: `${API_URL}/api/v1/approvals`,
+    url: buildApiUrl('/api/v1/approvals'),
     method: 'POST',
     body: requestBody,
     errorMessage: '문서 저장에 실패했습니다.',
@@ -293,7 +285,7 @@ export async function submitApproval(id: number): Promise<{
   error?: string;
 }> {
   const result = await executeServerAction({
-    url: `${API_URL}/api/v1/approvals/${id}/submit`,
+    url: buildApiUrl(`/api/v1/approvals/${id}/submit`),
     method: 'POST',
     body: {},
     errorMessage: '문서 상신에 실패했습니다.',
@@ -349,7 +341,7 @@ export async function getApprovalById(id: number): Promise<{
 }> {
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   const result = await executeServerAction<any>({
-    url: `${API_URL}/api/v1/approvals/${id}`,
+    url: buildApiUrl(`/api/v1/approvals/${id}`),
     errorMessage: '문서 조회에 실패했습니다.',
   });
   if (!result.success || !result.data) return { success: false, error: result.error };
@@ -397,7 +389,7 @@ export async function updateApproval(id: number, formData: DocumentFormData): Pr
   };
 
   const result = await executeServerAction<ApprovalCreateResponse>({
-    url: `${API_URL}/api/v1/approvals/${id}`,
+    url: buildApiUrl(`/api/v1/approvals/${id}`),
     method: 'PATCH',
     body: requestBody,
     errorMessage: '문서 수정에 실패했습니다.',
@@ -449,7 +441,7 @@ export async function deleteApproval(id: number): Promise<{
   error?: string;
 }> {
   const result = await executeServerAction({
-    url: `${API_URL}/api/v1/approvals/${id}`,
+    url: buildApiUrl(`/api/v1/approvals/${id}`),
     method: 'DELETE',
     errorMessage: '문서 삭제에 실패했습니다.',
   });