Fix age calculation: inject today's date, add Korean/international age

- Prepend today's date to system prompt on every call so LLM uses correct year
- Calculate both Korean age (현재연도-출생연도+1) and 만 나이 with exact birthday handling
- Support full date (생년월일) and year-only (생년) profile values
- Update remember_user_info to encourage storing full birth date
- Strengthen get_current_date tool description for age-related queries

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

services/agent/agent_service.py

@@ -74,12 +74,37 @@ class AgentService:
         llm_with_tools = chat_model.bind_tools(tools)
 
         async def call_model(state: MessagesState, config: RunnableConfig) -> dict:
-            system_content = self._system_prompt
+            from datetime import date
+            system_content = f"오늘 날짜: {date.today().isoformat()}\n\n" + self._system_prompt
             if self._profile_repo:
                 profile = self._profile_repo.get_all(self._user_id)
                 if profile:
-                    lines = "\n".join(f"- {k}: {v}" for k, v in profile.items())
-                    system_content += f"\n\n## 사용자 정보 (이전 대화에서 기억된 내용)\n{lines}"
+                    import re
+                    from datetime import date
+                    today = date.today()
+                    current_year = today.year
+                    _DATE_KEYS = ("생년월일", "생년", "생일")
+                    lines = []
+                    for k, v in profile.items():
+                        if any(term in k for term in _DATE_KEYS):
+                            full_date = re.search(r'(\d{4})[년\-/.]\s*(\d{1,2})[월\-/.]\s*(\d{1,2})', v)
+                            year_only = re.search(r'\b(19|20)\d{2}\b', v)
+                            age_key = re.sub(r'생년월일|생년|생일', '나이', k)
+                            if full_date:
+                                by, bm, bd = int(full_date.group(1)), int(full_date.group(2)), int(full_date.group(3))
+                                korean_age = current_year - by + 1
+                                intl_age = current_year - by - (1 if today < date(current_year, bm, bd) else 0)
+                                lines.append(f"- {age_key}: 한국 나이 {korean_age}세, 만 {intl_age}세")
+                            elif year_only:
+                                by = int(year_only.group())
+                                korean_age = current_year - by + 1
+                                intl_age = current_year - by
+                                lines.append(f"- {age_key}: 한국 나이 {korean_age}세, 만 {intl_age}~{intl_age - 1}세 (생일에 따라 다름)")
+                            else:
+                                lines.append(f"- {k}: {v}")
+                        else:
+                            lines.append(f"- {k}: {v}")
+                    system_content += f"\n\n## 사용자 정보 (이전 대화에서 기억된 내용)\n" + "\n".join(lines)
             msgs = [SystemMessage(content=system_content)] + state["messages"]
             thinking_acc, content_acc, tool_calls_acc = "", "", []
             async for chunk in llm_with_tools.astream(msgs, config):