feat: gpt 프롬프트 반환

src/main/java/com/project/oof/storage/service/ChatHistoryService.java

@@ -0,0 +1,26 @@
+package com.project.oof.storage.service;
+
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+@Service
+public class ChatHistoryService {
+
+    private final List<Map<String, String>> chatHistory = new ArrayList<>();
+
+    public void addMessage(String role, String content) {
+        chatHistory.add(Map.of("role", role, "content", content));
+    }
+
+    public List<Map<String, String>> getChatHistory() {
+        return new ArrayList<>(chatHistory); // 복사본 반환
+    }
+
+    // 대화 기록 초기화 (옵션)
+    public void clearChatHistory() {
+        chatHistory.clear();
+    }
+}