feat: fetchWrapper 마이그레이션 및 토큰 리프레시 캐싱 구현

- 40+ actions.ts 파일을 fetchWrapper 패턴으로 마이그레이션
- 토큰 리프레시 캐싱 로직 추가 (refresh-token.ts)
- ApiErrorContext 추가로 전역 에러 처리 개선
- HR EmployeeForm 컴포넌트 개선
- 참조함(ReferenceBox) 기능 수정
- juil 테스트 URL 페이지 추가
- claudedocs 문서 업데이트

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/components/settings/SubscriptionManagement/actions.ts

@@ -1,40 +1,42 @@
 'use server';
 
-import { cookies } from 'next/headers';
+import { serverFetch } from '@/lib/api/fetch-wrapper';
 import type { SubscriptionApiData, UsageApiData, SubscriptionInfo } from './types';
 import { transformApiToFrontend } from './utils';
 
-// ===== API 헤더 생성 =====
-async function getApiHeaders(): Promise<HeadersInit> {
-  const cookieStore = await cookies();
-  const token = cookieStore.get('access_token')?.value;
-
-  return {
-    'Accept': 'application/json',
-    'Content-Type': 'application/json',
-    'Authorization': token ? `Bearer ${token}` : '',
-    'X-API-KEY': process.env.API_KEY || '',
-  };
-}
-
 // ===== 현재 활성 구독 조회 =====
 export async function getCurrentSubscription(): Promise<{
   success: boolean;
   data: SubscriptionApiData | null;
   error?: string;
+  __authError?: boolean;
 }> {
   try {
-    const headers = await getApiHeaders();
-
-    const response = await fetch(
+    const { response, error } = await serverFetch(
       `${process.env.NEXT_PUBLIC_API_URL}/api/v1/subscriptions/current`,
       {
         method: 'GET',
-        headers,
         cache: 'no-store',
       }
     );
 
+    if (error) {
+      return {
+        success: false,
+        data: null,
+        error: error.message,
+        __authError: error.code === 'UNAUTHORIZED',
+      };
+    }
+
+    if (!response) {
+      return {
+        success: false,
+        data: null,
+        error: '구독 정보를 불러오는데 실패했습니다.',
+      };
+    }
+
     const result = await response.json();
 
     if (!response.ok || !result.success) {
@@ -64,19 +66,34 @@ export async function getUsage(): Promise<{
   success: boolean;
   data: UsageApiData | null;
   error?: string;
+  __authError?: boolean;
 }> {
   try {
-    const headers = await getApiHeaders();
-
-    const response = await fetch(
+    const { response, error } = await serverFetch(
       `${process.env.NEXT_PUBLIC_API_URL}/api/v1/subscriptions/usage`,
       {
         method: 'GET',
-        headers,
         cache: 'no-store',
       }
     );
 
+    if (error) {
+      return {
+        success: false,
+        data: null,
+        error: error.message,
+        __authError: error.code === 'UNAUTHORIZED',
+      };
+    }
+
+    if (!response) {
+      return {
+        success: false,
+        data: null,
+        error: '사용량 정보를 불러오는데 실패했습니다.',
+      };
+    }
+
     const result = await response.json();
 
     if (!response.ok || !result.success) {
@@ -108,19 +125,32 @@ export async function cancelSubscription(
 ): Promise<{
   success: boolean;
   error?: string;
+  __authError?: boolean;
 }> {
   try {
-    const headers = await getApiHeaders();
-
-    const response = await fetch(
+    const { response, error } = await serverFetch(
       `${process.env.NEXT_PUBLIC_API_URL}/api/v1/subscriptions/${id}/cancel`,
       {
         method: 'POST',
-        headers,
         body: JSON.stringify({ reason }),
       }
     );
 
+    if (error) {
+      return {
+        success: false,
+        error: error.message,
+        __authError: error.code === 'UNAUTHORIZED',
+      };
+    }
+
+    if (!response) {
+      return {
+        success: false,
+        error: '구독 취소에 실패했습니다.',
+      };
+    }
+
     const result = await response.json();
 
     if (!response.ok || !result.success) {
@@ -147,19 +177,32 @@ export async function requestDataExport(
   success: boolean;
   data?: { id: number; status: string };
   error?: string;
+  __authError?: boolean;
 }> {
   try {
-    const headers = await getApiHeaders();
-
-    const response = await fetch(
+    const { response, error } = await serverFetch(
       `${process.env.NEXT_PUBLIC_API_URL}/api/v1/subscriptions/export`,
       {
         method: 'POST',
-        headers,
         body: JSON.stringify({ export_type: exportType }),
       }
     );
 
+    if (error) {
+      return {
+        success: false,
+        error: error.message,
+        __authError: error.code === 'UNAUTHORIZED',
+      };
+    }
+
+    if (!response) {
+      return {
+        success: false,
+        error: '내보내기 요청에 실패했습니다.',
+      };
+    }
+
     const result = await response.json();
 
     if (!response.ok || !result.success) {