fix: 마음기록 새로고침 오류 수정

frontend/ongi/lib/screens/bottom_nav.dart

@@ -28,7 +28,7 @@ class _BottomNavScreenState extends State<BottomNavScreen> {
   final List<Widget> _screens = [
     HomeScreen(key: homeScreenKey),
     HealthHomeScreen(key: healthHomeScreenKey),
-    const PhotoCalendarScreen(),
+    PhotoCalendarScreen(key: photoCalendarScreenKey),
     const ProfileScreen(),
   ];
 
@@ -125,6 +125,20 @@ class _BottomNavScreenState extends State<BottomNavScreen> {
     }
   }
 
+  Future<void> _refreshPhotoData() async {
+    // 마음기록(앨범) 화면의 데이터를 백그라운드에서 새로고침
+    try {
+      final photoCalendarScreenState = photoCalendarScreenKey.currentState;
+      if (photoCalendarScreenState != null) {
+        // 백그라운드에서 조용히 새로고침 수행
+        await photoCalendarScreenState.refreshPhotoCalendar();
+      }
+    } catch (e) {
+      // 새로고침 실패 시 조용히 처리
+      print('마음기록 데이터 새로고침 실패 (조용히 처리됨): $e');
+    }
+  }
+
   void _onTabTapped(int index) {
     setState(() {
       _currentIndex = index;
@@ -143,6 +157,11 @@ class _BottomNavScreenState extends State<BottomNavScreen> {
     if (index == 1) {
       _refreshHealthData();
     }
+
+    // 마음기록(앨범) 탭(index=2) 선택 시 백그라운드 새로고침
+    if (index == 2) {
+      _refreshPhotoData();
+    }
   }
 
   Future<void> _onAddRecordTapped() async {

frontend/ongi/lib/screens/home/home_degree_graph.dart

@@ -383,7 +383,7 @@ class _HomeDegreeGraph extends State<HomeDegreeGraph> {
                     ),
                   ),
                   Text(
-                    item.formattedDate ?? '',
+                    item.formattedDate,
                     style: const TextStyle(
                       color: Colors.grey,
                       fontSize: 12,

frontend/ongi/lib/screens/photo/check_record_screen.dart

@@ -7,8 +7,6 @@ import 'package:geolocator/geolocator.dart';
 import 'package:geocoding/geocoding.dart';
 import 'package:ongi/screens/photo/detail_record_screen.dart';
 
-import '../home/home_screen.dart';
-
 class CheckRecordScreen extends StatefulWidget {
   final String backImagePath;
   final String? frontImagePath;

frontend/ongi/lib/screens/photo/photo_calendar_screen.dart

@@ -14,6 +14,9 @@ class PhotoCalendarScreen extends StatefulWidget {
   State<PhotoCalendarScreen> createState() => _PhotoCalendarScreenState();
 }
 
+// 전역 키를 사용해서 외부에서 새로고침 메서드에 접근할 수 있도록 함
+final GlobalKey<_PhotoCalendarScreenState> photoCalendarScreenKey = GlobalKey<_PhotoCalendarScreenState>();
+
 class _PhotoCalendarScreenState extends State<PhotoCalendarScreen> {
   String _currentView = 'calendar';
   DateTime _focusedDay = DateTime.now();
@@ -31,7 +34,22 @@ class _PhotoCalendarScreenState extends State<PhotoCalendarScreen> {
     _fetchCalendarDataForMonth(_focusedDay);
   }
 
-  void _goBackToCalendar() => setState(() => _currentView = 'calendar');
+  // 외부에서 호출 가능한 새로고침 메서드
+  Future<void> refreshPhotoCalendar() async {
+    try {
+      await _fetchCalendarDataForMonth(_focusedDay);
+    } catch (e) {
+      print('마음기록 캘린더 새로고침 실패: $e');
+    }
+  }
+
+  void _goBackToCalendar() {
+    setState(() => _currentView = 'calendar');
+    // 캘린더로 복귀 시 자동 새로고침
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      refreshPhotoCalendar();
+    });
+  }
 
   Widget _dayCellBuilder(
     BuildContext context,

frontend/ongi/lib/services/pain_service.dart

@@ -1,5 +1,4 @@
 import 'dart:convert';
-import 'dart:math';
 import 'package:http/http.dart' as http;
 import '../utils/prefs_manager.dart';
 

frontend/ongi/lib/services/temperature_summary_service.dart

@@ -1,6 +1,5 @@
 import 'dart:convert';
 import 'package:http/http.dart' as http;
-import 'package:flutter/material.dart';
 
 class TemperatureSummaryService {
   // API URL