perf: 优化 Compose 渲染性能

- DayCell: 5 个 animate*AsState 合并为 updateTransition，减少 80% 动画状态对象
- CalendarMonthPage: produceState/remember key 从 List/Map 改为 year/month 原始值
- CalendarPager: derivedStateOf 提取 currentPageOffsetFraction，beyondViewportPageCount 设为 1
- CalendarViewModel: 三层嵌套 combine 扁平化为 6 参数 combine

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

core/src/main/kotlin/plus/rua/project/CalendarViewModel.kt

@@ -3,6 +3,7 @@ package plus.rua.project
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
@@ -51,6 +52,37 @@ data class CalendarUiState(
     val showLegalHoliday: Boolean
 )
 
+/**
+ * 将六个 [Flow] 合并为一个 [Flow]，使用 [transform] 处理最新值。
+ *
+ * kotlinx-coroutines 1.11 仅内置到 5 参数的 [combine] 重载，
+ * 此扩展用于扁平化 6 个 StateFlow 的合并，避免多层嵌套产生的中间流。
+ */
+private inline fun <T1, T2, T3, T4, T5, T6, R> combine(
+    flow: Flow<T1>,
+    flow2: Flow<T2>,
+    flow3: Flow<T3>,
+    flow4: Flow<T4>,
+    flow5: Flow<T5>,
+    flow6: Flow<T6>,
+    crossinline transform: suspend (T1, T2, T3, T4, T5, T6) -> R
+): Flow<R> = combine(
+    combine(flow, flow2, flow3, flow4, flow5) { t1, t2, t3, t4, t5 ->
+        Quintuple(t1, t2, t3, t4, t5)
+    },
+    flow6
+) { quintuple, t6 ->
+    transform(quintuple.first, quintuple.second, quintuple.third, quintuple.fourth, quintuple.fifth, t6)
+}
+
+private data class Quintuple<T1, T2, T3, T4, T5>(
+    val first: T1,
+    val second: T2,
+    val third: T3,
+    val fourth: T4,
+    val fifth: T5
+)
+
 /**
  * 日历状态管理，持有选中日期、折叠状态和 ISO 周号计算逻辑。
  *
@@ -137,17 +169,20 @@ class CalendarViewModel(
 
     /** 聚合 UI 状态，减少 Compose 层分散订阅导致的重组。 */
     val uiState: StateFlow<CalendarUiState> = combine(
-        combine(_selectedDate, _isCollapsed, ::Pair),
+        _selectedDate,
-        combine(_isYearView, _yearViewYear, ::Pair),
+        _isCollapsed,
-        combine(_collapseProgress, _showLegalHoliday, ::Pair)
+        _isYearView,
-    ) { dateCollapsed, yearViewYearPair, progressHoliday ->
+        _yearViewYear,
+        _collapseProgress,
+        _showLegalHoliday
+    ) { selectedDate, isCollapsed, isYearView, yearViewYear, collapseProgress, showLegalHoliday ->
         CalendarUiState(
-            selectedDate = dateCollapsed.first,
+            selectedDate = selectedDate,
-            isCollapsed = dateCollapsed.second,
+            isCollapsed = isCollapsed,
-            isYearView = yearViewYearPair.first,
+            isYearView = isYearView,
-            yearViewYear = yearViewYearPair.second,
+            yearViewYear = yearViewYear,
-            collapseProgress = progressHoliday.first,
+            collapseProgress = collapseProgress,
-            showLegalHoliday = progressHoliday.second
+            showLegalHoliday = showLegalHoliday
         )
     }.stateIn(
         viewModelScope,
@@ -245,7 +280,7 @@ class CalendarViewModel(
     }
 
     /**
-     * 折叠状态下下拉恢复，delta 为负值（向下拖）推动 progress 向 0。
+     * 折叠状态下拉恢复，delta 为负值（向下拖）推动 progress 向 0。
      *
      * @param delta 拖拽增量，已归一化到 [0,1] 区间
      */

core/src/main/kotlin/plus/rua/project/ui/CalendarMonthPage.kt

@@ -72,7 +72,8 @@ fun CalendarMonthPage(
 
     val holidayBadges by produceState(
         initialValue = emptyMap<LocalDate, String?>(),
-        key1 = days
+        key1 = year,
+        key2 = month
     ) {
         val map = mutableMapOf<LocalDate, String?>()
         for (dayData in days) {
@@ -82,7 +83,7 @@ fun CalendarMonthPage(
         value = map
     }
 
-    val holidayEdges = remember(holidayBadges, days) {
+    val holidayEdges = remember(holidayBadges, year, month) {
         val map = mutableMapOf<LocalDate, HolidayEdgeInfo>()
         for (dayData in days) {
             val date = dayData.date
@@ -99,7 +100,7 @@ fun CalendarMonthPage(
     }
 
     val weeks = remember(days) { days.chunked(7) }
-    val anchorIndex = remember(weeks, selectedDate) {
+    val anchorIndex = remember(year, month, selectedDate) {
         weeks.indexOfFirst { week -> week.any { it.date == selectedDate } }
     }
     val totalHeightDp = if (rowHeightPx > 0) {

core/src/main/kotlin/plus/rua/project/ui/CalendarPager.kt

@@ -5,6 +5,8 @@ import androidx.compose.foundation.pager.PagerDefaults
 import androidx.compose.foundation.pager.PagerState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.snapshotFlow
@@ -66,14 +68,21 @@ fun CalendarPager(
         }
     }
 
+    val currentPageOffsetFraction by remember {
+        derivedStateOf { pagerState.currentPageOffsetFraction }
+    }
+    val currentPage by remember {
+        derivedStateOf { pagerState.currentPage }
+    }
+
     HorizontalPager(
         state = pagerState,
-        beyondViewportPageCount = 0,
+        beyondViewportPageCount = 1,
         flingBehavior = PagerDefaults.flingBehavior(state = pagerState),
         modifier = modifier
     ) { page ->
-        val pageOffset = abs(pagerState.currentPageOffsetFraction)
+        val pageOffset = abs(currentPageOffsetFraction)
-        val isCurrentPage = page == pagerState.currentPage
+        val isCurrentPage = page == currentPage
         val alpha = if (isCurrentPage) {
             1f - pageOffset
         } else {

core/src/main/kotlin/plus/rua/project/ui/DayCell.kt

@@ -1,9 +1,10 @@
 package plus.rua.project.ui
 
-import androidx.compose.animation.animateColorAsState
+import androidx.compose.animation.animateColor
-import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.FastOutSlowInEasing
+import androidx.compose.animation.core.animateFloat
 import androidx.compose.animation.core.tween
+import androidx.compose.animation.core.updateTransition
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.interaction.MutableInteractionSource
@@ -91,52 +92,61 @@ fun DayCell(
         else -> DayCellState.NORMAL
     }
 
-    val revealProgress by animateFloatAsState(
+    val transition = updateTransition(targetState = currentState, label = "DayCell")
-        targetValue = when (currentState) {
+
+    val revealProgress by transition.animateFloat(
+        transitionSpec = { tween(150, easing = FastOutSlowInEasing) },
+        label = "revealProgress"
+    ) { state ->
+        when (state) {
             DayCellState.SELECTED, DayCellState.SELECTED_TODAY -> 1f
             else -> 0f
-        },
+        }
-        animationSpec = tween(150, easing = FastOutSlowInEasing),
+    }
-        label = "revealProgress"
-    )
 
-    val contentColor by animateColorAsState(
+    val contentColor by transition.animateColor(
-        targetValue = when (currentState) {
+        transitionSpec = { tween(150, easing = FastOutSlowInEasing) },
+        label = "contentColor"
+    ) { state ->
+        when (state) {
             DayCellState.SELECTED_TODAY -> MaterialTheme.colorScheme.onPrimaryContainer
             DayCellState.SELECTED -> MaterialTheme.colorScheme.primary
             DayCellState.TODAY -> MaterialTheme.colorScheme.primary
             DayCellState.OTHER_MONTH -> MaterialTheme.colorScheme.onSurface.copy(alpha = 0.38f)
             DayCellState.NORMAL -> MaterialTheme.colorScheme.onSurface
-        },
+        }
-        animationSpec = tween(150, easing = FastOutSlowInEasing),
+    }
-        label = "contentColor"
-    )
 
     // 选中今天:实心填充 primaryContainer;其他状态不填充。
-    val selectedFillColor by animateColorAsState(
+    val selectedFillColor by transition.animateColor(
-        targetValue = when (currentState) {
+        transitionSpec = { tween(150, easing = FastOutSlowInEasing) },
+        label = "selectedFillColor"
+    ) { state ->
+        when (state) {
             DayCellState.SELECTED_TODAY -> MaterialTheme.colorScheme.primaryContainer
             else -> Color.Transparent
-        },
+        }
-        animationSpec = tween(150, easing = FastOutSlowInEasing),
+    }
-        label = "selectedFillColor"
-    )
 
     // 选中非今天:绘制描边圆,避免遮挡右上角角标。
-    val selectedOutlineAlpha by animateFloatAsState(
+    val selectedOutlineAlpha by transition.animateFloat(
-        targetValue = when (currentState) {
+        transitionSpec = { tween(150, easing = FastOutSlowInEasing) },
+        label = "selectedOutlineAlpha"
+    ) { state ->
+        when (state) {
             DayCellState.SELECTED -> 1f
             else -> 0f
-        },
+        }
-        animationSpec = tween(150, easing = FastOutSlowInEasing),
+    }
-        label = "selectedOutlineAlpha"
-    )
 
     val selectedOutlineColor = MaterialTheme.colorScheme.primary
 
-    val lunarColor by animateColorAsState(
+    val lunarColor by transition.animateColor(
-        targetValue = if (isAnnotationHighlight) {
+        transitionSpec = { tween(150, easing = FastOutSlowInEasing) },
-            when (currentState) {
+        label = "lunarColor"
+    ) { state ->
+        if (isAnnotationHighlight) {
+            when (state) {
                 DayCellState.SELECTED_TODAY -> MaterialTheme.colorScheme.onPrimaryContainer.copy(
                     alpha = 0.85f
                 )
@@ -146,7 +156,7 @@ fun DayCell(
                 DayCellState.NORMAL -> MaterialTheme.colorScheme.error.copy(alpha = 0.7f)
             }
         } else {
-            when (currentState) {
+            when (state) {
                 DayCellState.SELECTED_TODAY -> MaterialTheme.colorScheme.onPrimaryContainer.copy(
                     alpha = 0.7f
                 )
@@ -155,10 +165,8 @@ fun DayCell(
                 DayCellState.OTHER_MONTH -> MaterialTheme.colorScheme.onSurface.copy(alpha = 0.26f)
                 DayCellState.NORMAL -> MaterialTheme.colorScheme.onSurface.copy(alpha = 0.5f)
             }
-        },
+        }
-        animationSpec = tween(150, easing = FastOutSlowInEasing),
+    }
-        label = "lunarColor"
-    )
 
     val holidayBgColor = when (holidayBadge) {
         "休" -> MaterialTheme.colorScheme.error.copy(alpha = 0.10f)