perf: DayCell produceState 上移到页面级，减少协程数量

CalendarMonthPage 统一预计算整月 42 天的 lunarData（1 个协程），
通过参数传入 DayCell，避免每个单元格独立启动 produceState（42 协程）。

- holidayBadges produceState 扩展为 lunarDataMap，存储完整 DayCellInfo
- DayCell 添加可选 lunarData 参数，条件分支调用 DayCellImpl
- WeekPager 保持向后兼容（不传 lunarData 时内部获取）

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

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

@@ -25,6 +25,7 @@ import kotlinx.datetime.LocalDate
 import kotlinx.datetime.minus
 import kotlinx.datetime.number
 import kotlinx.datetime.plus
+import plus.rua.project.DayCellInfo
 import plus.rua.project.LunarCache
 import plus.rua.project.ShiftKind
 
@@ -69,27 +70,26 @@ fun CalendarMonthPage(
     val density = LocalDensity.current
     val interactionSource = remember { MutableInteractionSource() }
 
-    val holidayBadges by produceState(
-        initialValue = emptyMap<LocalDate, String?>(),
+    val lunarDataMap by produceState(
+        initialValue = emptyMap<LocalDate, DayCellInfo>(),
         key1 = year,
         key2 = month
     ) {
-        val map = mutableMapOf<LocalDate, String?>()
+        val map = mutableMapOf<LocalDate, DayCellInfo>()
         for (dayData in days) {
-            val info = LunarCache.default.getOrCompute(dayData.date)
-            map[dayData.date] = info.holidayBadge
+            map[dayData.date] = LunarCache.default.getOrCompute(dayData.date)
         }
         value = map
     }
 
-    val holidayEdges = remember(holidayBadges, year, month) {
+    val holidayEdges = remember(lunarDataMap, year, month) {
         val map = mutableMapOf<LocalDate, HolidayEdgeInfo>()
         for (dayData in days) {
             val date = dayData.date
-            val badge = holidayBadges[date]
+            val badge = lunarDataMap[date]?.holidayBadge
             if (badge == null) continue
-            val prevBadge = holidayBadges[date.minus(DatePeriod(days = 1))]
-            val nextBadge = holidayBadges[date.plus(DatePeriod(days = 1))]
+            val prevBadge = lunarDataMap[date.minus(DatePeriod(days = 1))]?.holidayBadge
+            val nextBadge = lunarDataMap[date.plus(DatePeriod(days = 1))]?.holidayBadge
             map[date] = HolidayEdgeInfo(
                 isStart = prevBadge != badge,
                 isEnd = nextBadge != badge
@@ -128,6 +128,7 @@ fun CalendarMonthPage(
                     shiftKindAt = shiftKindAt,
                     showLegalHoliday = showLegalHoliday,
                     holidayEdges = holidayEdges,
+                    lunarDataMap = lunarDataMap,
                     onDateClick = onDateClick,
                     onRowHeightMeasured = onRowHeightMeasured,
                     interactionSource = interactionSource
@@ -150,6 +151,7 @@ private fun WeekRow(
     shiftKindAt: (LocalDate) -> ShiftKind?,
     showLegalHoliday: Boolean,
     holidayEdges: Map<LocalDate, HolidayEdgeInfo>,
+    lunarDataMap: Map<LocalDate, DayCellInfo>,
     onDateClick: (LocalDate) -> Unit,
     onRowHeightMeasured: ((Int) -> Unit)?,
     interactionSource: MutableInteractionSource,
@@ -235,7 +237,8 @@ private fun WeekRow(
                         holidayEdgeInfo = holidayEdges[dayData.date],
                         onClick = { onDateClick(dayData.date) },
                         modifier = Modifier.weight(1f),
-                        interactionSource = interactionSource
+                        interactionSource = interactionSource,
+                        lunarData = lunarDataMap[dayData.date]
                     )
                 }
             }

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

@@ -72,15 +72,61 @@ fun DayCell(
     onClick: () -> Unit,
     modifier: Modifier = Modifier,
     interactionSource: MutableInteractionSource = remember { MutableInteractionSource() },
-    lunarCache: LunarCache = LunarCache.default
+    lunarCache: LunarCache = LunarCache.default,
+    lunarData: DayCellInfo? = null,
 ) {
-    val lunarData by produceState(
-        initialValue = DayCellInfo("", false, null),
-        key1 = date,
-        key2 = lunarCache
-    ) {
-        value = lunarCache.getOrCompute(date)
+    if (lunarData != null) {
+        DayCellImpl(
+            date = date,
+            isCurrentMonth = isCurrentMonth,
+            isSelected = isSelected,
+            isToday = isToday,
+            shiftKind = shiftKind,
+            showLegalHoliday = showLegalHoliday,
+            holidayEdgeInfo = holidayEdgeInfo,
+            onClick = onClick,
+            modifier = modifier,
+            interactionSource = interactionSource,
+            lunarData = lunarData,
+        )
+    } else {
+        val computed by produceState(
+            initialValue = DayCellInfo("", false, null),
+            key1 = date,
+            key2 = lunarCache
+        ) {
+            value = lunarCache.getOrCompute(date)
+        }
+        DayCellImpl(
+            date = date,
+            isCurrentMonth = isCurrentMonth,
+            isSelected = isSelected,
+            isToday = isToday,
+            shiftKind = shiftKind,
+            showLegalHoliday = showLegalHoliday,
+            holidayEdgeInfo = holidayEdgeInfo,
+            onClick = onClick,
+            modifier = modifier,
+            interactionSource = interactionSource,
+            lunarData = computed,
+        )
     }
+}
+
+@Composable
+private fun DayCellImpl(
+    date: LocalDate,
+    isCurrentMonth: Boolean,
+    isSelected: Boolean,
+    isToday: Boolean,
+    shiftKind: ShiftKind?,
+    showLegalHoliday: Boolean,
+    holidayEdgeInfo: HolidayEdgeInfo?,
+    onClick: () -> Unit,
+    modifier: Modifier,
+    interactionSource: MutableInteractionSource,
+    lunarData: DayCellInfo,
+) {
     val annotationText = lunarData.annotationText
     val isAnnotationHighlight = lunarData.isAnnotationHighlight
     val holidayBadge = lunarData.holidayBadge