fix: vobject 의존성 추가 + calendar 파싱 icalendar fallback

CalDAV 3.x에서 vobject 분리됨 → 이벤트 파싱 실패 원인.
vobject 설치 + icalendar fallback 파싱 추가.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

nanoclaude/requirements.txt

@@ -5,3 +5,4 @@ pydantic-settings==2.5.0
 aiosqlite==0.20.0
 python-multipart==0.0.9
 caldav>=1.3.0
+vobject>=0.9.8

nanoclaude/tools/calendar_tool.py

@@ -31,8 +31,9 @@ def _get_client():
 
 
 def _parse_event(event) -> dict:
-    """VEVENT → dict."""
+    """VEVENT → dict. vobject 있으면 사용, 없으면 icalendar fallback."""
     try:
+        # vobject 방식
         vevent = event.vobject_instance.vevent
         summary = str(vevent.summary.value) if hasattr(vevent, "summary") else "(제목 없음)"
         dtstart = vevent.dtstart.value
@@ -43,7 +44,24 @@ def _parse_event(event) -> dict:
 
         return {"summary": summary, "start": start_str, "end": end_str}
     except Exception:
-        return {"summary": "(파싱 실패)", "start": "", "end": ""}
+        pass
+
+    # fallback: icalendar 라이브러리로 raw data 파싱
+    try:
+        from icalendar import Calendar
+        cal = Calendar.from_ical(event.data)
+        for comp in cal.walk():
+            if comp.name == "VEVENT":
+                summary = str(comp.get("summary", "(제목 없음)"))
+                dtstart = comp.get("dtstart")
+                dtend = comp.get("dtend")
+                start_str = dtstart.dt.strftime("%Y-%m-%d %H:%M") if dtstart else ""
+                end_str = dtend.dt.strftime("%Y-%m-%d %H:%M") if dtend else ""
+                return {"summary": summary, "start": start_str, "end": end_str}
+    except Exception:
+        pass
+
+    return {"summary": "(파싱 실패)", "start": "", "end": ""}
 
 
 async def today() -> dict: