Flutter 앱: 달력 팝업 UI 개선

- 달력 열기 애니메이션 추가 (아래로 부드럽게 펼쳐짐)
- 툴바 영역 오버레이 제외 (툴바 아래부터 반투명 배경)
- 년월 텍스트 가운데 고정, 화살표는 옆에 별도 위치

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

app/lib/views/schedule/schedule_view.dart

@@ -118,10 +118,14 @@ class _ScheduleViewState extends ConsumerState<ScheduleView> {
             ),
           ],
         ),
-        // 달력 팝업 오버레이
+        // 달력 팝업 오버레이 (툴바 아래부터)
         if (_showCalendar) ...[
-          // 배경 오버레이
-          Positioned.fill(
+          // 배경 오버레이 (툴바 제외)
+          Positioned(
+            top: MediaQuery.of(context).padding.top + 56,
+            left: 0,
+            right: 0,
+            bottom: 0,
             child: GestureDetector(
               onTap: () {
                 setState(() {
@@ -134,7 +138,7 @@ class _ScheduleViewState extends ConsumerState<ScheduleView> {
               ),
             ),
           ),
-          // 달력 팝업
+          // 달력 팝업 (애니메이션)
           Positioned(
             top: MediaQuery.of(context).padding.top + 56,
             left: 0,
@@ -196,7 +200,11 @@ class _ScheduleViewState extends ConsumerState<ScheduleView> {
               ),
               // 년월 표시
               Expanded(
-                child: GestureDetector(
+                child: Stack(
+                  alignment: Alignment.center,
+                  children: [
+                    // 년월 텍스트 (가운데 고정)
+                    GestureDetector(
                       onTap: _showCalendar
                           ? () {
                               setState(() {
@@ -205,11 +213,7 @@ class _ScheduleViewState extends ConsumerState<ScheduleView> {
                               });
                             }
                           : null,
-                  child: Center(
-                    child: Row(
-                      mainAxisSize: MainAxisSize.min,
-                      children: [
-                        Text(
+                      child: Text(
                         '${displayDate.year}년 ${displayDate.month}월',
                         style: TextStyle(
                           fontSize: 16,
@@ -219,9 +223,20 @@ class _ScheduleViewState extends ConsumerState<ScheduleView> {
                               : AppColors.textPrimary,
                         ),
                       ),
-                        if (_showCalendar) ...[
-                          const SizedBox(width: 4),
-                          Icon(
+                    ),
+                    // 화살표 (년월 옆에 위치)
+                    if (_showCalendar)
+                      Positioned(
+                        // 년월 텍스트 너비의 절반 + 여백
+                        left: MediaQuery.of(context).size.width / 2 - 48 + 52,
+                        child: GestureDetector(
+                          onTap: () {
+                            setState(() {
+                              _showYearMonthPicker = !_showYearMonthPicker;
+                              _yearRangeStart = (_calendarViewDate.year ~/ 12) * 12;
+                            });
+                          },
+                          child: Icon(
                             _showYearMonthPicker
                                 ? Icons.keyboard_arrow_up
                                 : Icons.keyboard_arrow_down,
@@ -230,10 +245,9 @@ class _ScheduleViewState extends ConsumerState<ScheduleView> {
                                 ? AppColors.primary
                                 : AppColors.textPrimary,
                           ),
-                        ],
-                      ],
                         ),
                       ),
+                  ],
                 ),
               ),
               // 다음 월
@@ -271,7 +285,23 @@ class _ScheduleViewState extends ConsumerState<ScheduleView> {
 
   /// 달력 팝업 빌드
   Widget _buildCalendarPopup(ScheduleState state, ScheduleController controller) {
-    return Material(
+    return TweenAnimationBuilder<double>(
+      duration: const Duration(milliseconds: 200),
+      curve: Curves.easeOut,
+      tween: Tween(begin: 0.0, end: 1.0),
+      builder: (context, value, child) {
+        return ClipRect(
+          child: Align(
+            alignment: Alignment.topCenter,
+            heightFactor: value,
+            child: Opacity(
+              opacity: value,
+              child: child,
+            ),
+          ),
+        );
+      },
+      child: Material(
         color: Colors.white,
         elevation: 8,
         child: AnimatedCrossFade(
@@ -282,6 +312,7 @@ class _ScheduleViewState extends ConsumerState<ScheduleView> {
           firstChild: _buildCalendarGrid(state, controller),
           secondChild: _buildYearMonthPicker(),
         ),
+      ),
     );
   }