feat: 法定假日改为背景色显示，支持连续边缘圆角

- 移除右上角 Text 角标，改用整格淡色背景（"休"淡红、"班"淡蓝）
- 连续假日自动边缘圆角：开头左边、结尾右边、中间无、单个四边
- 排班标记固定右上角，不再随 showLegalHoliday 切换位置

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

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

@@ -9,7 +9,9 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
 import androidx.compose.runtime.key
+import androidx.compose.runtime.produceState
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clipToBounds
@@ -24,6 +26,7 @@ import kotlinx.datetime.LocalDate
 import kotlinx.datetime.minus
 import kotlinx.datetime.number
 import kotlinx.datetime.plus
+import plus.rua.project.LunarCache
 import plus.rua.project.ShiftKind
 
 
@@ -42,7 +45,7 @@ import plus.rua.project.ShiftKind
  * @param rowHeightPx 从外层传入的锁定行高（像素），折叠过程中不变
  * @param effectiveWeeks 当前有效行数（含翻页插值），用于计算总高度
  * @param shiftKindAt 日期 → 个人轮班类型的查询闭包
- * @param showLegalHoliday 是否显示法定调休角标。详见 [DayCell] 的同名参数。
+ * @param showLegalHoliday 是否显示法定调休背景色。详见 [DayCell] 的同名参数。
  * @param onRowHeightMeasured 首次行高测量回调，外层据此锁定行高
  * @param modifier 外部布局修饰符
  */
@@ -67,6 +70,34 @@ fun CalendarMonthPage(
     val density = LocalDensity.current
     val interactionSource = remember { MutableInteractionSource() }
 
+    val holidayBadges by produceState(
+        initialValue = emptyMap<LocalDate, String?>(),
+        key1 = days
+    ) {
+        val map = mutableMapOf<LocalDate, String?>()
+        for (dayData in days) {
+            val info = LunarCache.default.getOrCompute(dayData.date)
+            map[dayData.date] = info.holidayBadge
+        }
+        value = map
+    }
+
+    val holidayEdges = remember(holidayBadges, days) {
+        val map = mutableMapOf<LocalDate, HolidayEdgeInfo>()
+        for (dayData in days) {
+            val date = dayData.date
+            val badge = holidayBadges[date]
+            if (badge == null) continue
+            val prevBadge = holidayBadges[date.minus(DatePeriod(days = 1))]
+            val nextBadge = holidayBadges[date.plus(DatePeriod(days = 1))]
+            map[date] = HolidayEdgeInfo(
+                isStart = prevBadge != badge,
+                isEnd = nextBadge != badge
+            )
+        }
+        map
+    }
+
     val weeks = remember(days) { days.chunked(7) }
     val anchorIndex = remember(weeks, selectedDate) {
         weeks.indexOfFirst { week -> week.any { it.date == selectedDate } }
@@ -96,6 +127,7 @@ fun CalendarMonthPage(
                     today = today,
                     shiftKindAt = shiftKindAt,
                     showLegalHoliday = showLegalHoliday,
+                    holidayEdges = holidayEdges,
                     onDateClick = onDateClick,
                     onRowHeightMeasured = onRowHeightMeasured,
                     interactionSource = interactionSource
@@ -117,6 +149,7 @@ private fun WeekRow(
     today: LocalDate,
     shiftKindAt: (LocalDate) -> ShiftKind?,
     showLegalHoliday: Boolean,
+    holidayEdges: Map<LocalDate, HolidayEdgeInfo>,
     onDateClick: (LocalDate) -> Unit,
     onRowHeightMeasured: ((Int) -> Unit)?,
     interactionSource: MutableInteractionSource,
@@ -197,6 +230,7 @@ private fun WeekRow(
                         isToday = dayData.date == today,
                         shiftKind = shiftKindAt(dayData.date),
                         showLegalHoliday = showLegalHoliday,
+                        holidayEdgeInfo = holidayEdges[dayData.date],
                         onClick = { onDateClick(dayData.date) },
                         modifier = Modifier.weight(1f),
                         interactionSource = interactionSource
@@ -212,6 +246,17 @@ private data class DayData(
     val isCurrentMonth: Boolean
 )
 
+/**
+ * 法定假日在连续序列中的边缘状态，用于决定背景圆角。
+ *
+ * @param isStart 是否为同类型连续假日的开始（前一天不是同类型）
+ * @param isEnd 是否为同类型连续假日的结束（后一天不是同类型）
+ */
+data class HolidayEdgeInfo(
+    val isStart: Boolean,
+    val isEnd: Boolean
+)
+
 @Suppress("DEPRECATION") // monthNumber 无替代 API，kotlinx-datetime 尚未提供新接口
 private fun generateMonthDays(year: Int, month: Int): List<DayData> {
     val firstOfMonth = LocalDate(year, month, 1)

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

@@ -32,7 +32,7 @@ import kotlin.math.abs
  * @param rowHeightPx 锁定行高（像素）
  * @param effectiveWeeks 当前有效行数（含翻页插值）
  * @param shiftKindAt 日期 → 个人轮班类型的查询闭包
- * @param showLegalHoliday 是否显示法定调休角标。详见 [DayCell] 的同名参数。
+ * @param showLegalHoliday 是否显示法定调休背景色。详见 [DayCell] 的同名参数。
  * @param onRowHeightMeasured 首次行高测量回调
  * @param pagerState 外层共享的 PagerState，用于保持翻页状态
  * @param modifier 外部布局修饰符

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

@@ -12,8 +12,8 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.aspectRatio
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -52,9 +52,10 @@ enum class DayCellState {
  * @param isSelected 是否为选中日期
  * @param isToday 是否为今天
  * @param shiftKind 个人轮班类型;null 表示不显示。与法定调休完全独立。
- * @param showLegalHoliday 是否显示法定调休角标。
- *   false(默认):排班放右上角,左上角空白,不显示法定调休。
- *   true:排班放左上角,法定调休放右上角(旧版布局)。
+ * @param showLegalHoliday 是否显示法定调休背景色。
+ *   false(默认):排班放右上角,不显示法定调休背景。
+ *   true:排班仍在右上角,法定假日以淡色背景显示("休"淡红,"班"淡蓝)。
+ * @param holidayEdgeInfo 假日在连续序列中的边缘状态,决定背景圆角。null 表示无假日。
  * @param onClick 点击回调
  * @param modifier 外部布局修饰符
  */
@@ -66,6 +67,7 @@ fun DayCell(
     isToday: Boolean,
     shiftKind: ShiftKind?,
     showLegalHoliday: Boolean,
+    holidayEdgeInfo: HolidayEdgeInfo? = null,
     onClick: () -> Unit,
     modifier: Modifier = Modifier,
     interactionSource: MutableInteractionSource = remember { MutableInteractionSource() },
@@ -158,16 +160,30 @@ fun DayCell(
         label = "lunarColor"
     )
 
-    val holidayBadgeColor = when (holidayBadge) {
-        "休" -> MaterialTheme.colorScheme.error
-        "班" -> MaterialTheme.colorScheme.primary
+    val holidayBgColor = when (holidayBadge) {
+        "休" -> MaterialTheme.colorScheme.error.copy(alpha = 0.10f)
+        "班" -> MaterialTheme.colorScheme.primary.copy(alpha = 0.08f)
         else -> Color.Transparent
     }
-    val holidayBadgeAlpha = if (isCurrentMonth) 1f else 0.38f
 
     Box(
         modifier = modifier.aspectRatio(1f)
     ) {
+        // 法定假日背景（最底层，与选中/今天状态叠加）
+        if (showLegalHoliday && holidayBadge != null) {
+            val holidayShape = when {
+                holidayEdgeInfo?.isStart == true && holidayEdgeInfo.isEnd -> RoundedCornerShape(8.dp)
+                holidayEdgeInfo?.isStart == true -> RoundedCornerShape(topStart = 8.dp, bottomStart = 8.dp)
+                holidayEdgeInfo?.isEnd == true -> RoundedCornerShape(topEnd = 8.dp, bottomEnd = 8.dp)
+                else -> RoundedCornerShape(0.dp)
+            }
+            Box(
+                modifier = Modifier
+                    .fillMaxSize()
+                    .padding(horizontal = 0.5.dp)
+                    .background(holidayBgColor, holidayShape)
+            )
+        }
         Box(
             modifier = Modifier
                 .fillMaxSize()
@@ -231,51 +247,16 @@ fun DayCell(
             }
             val shiftLabel = if (shiftKind == ShiftKind.WORK) "班" else "休"
             val shiftAlpha = if (isCurrentMonth) 1f else 0.38f
-            if (showLegalHoliday) {
-                Box(
-                    modifier = Modifier
-                        .align(Alignment.TopStart)
-                        .zIndex(1f)
-                        .padding(top = 1.dp, start = 2.dp)
-                        .background(shiftAccentColor.copy(alpha = 0.12f), CircleShape)
-                        .size(16.dp),
-                    contentAlignment = Alignment.Center
-                ) {
-                    Text(
-                        text = shiftLabel,
-                        color = shiftAccentColor.copy(alpha = shiftAlpha),
-                        fontSize = 9.sp,
-                        fontWeight = FontWeight.Bold,
-                        lineHeight = 9.sp
-                    )
-                }
-            } else {
-                Text(
-                    text = shiftLabel,
-                    color = shiftAccentColor.copy(alpha = shiftAlpha),
-                    fontSize = 9.sp,
-                    fontWeight = FontWeight.Bold,
-                    lineHeight = 9.sp,
-                    modifier = Modifier
-                        .align(Alignment.TopEnd)
-                        .zIndex(1f)
-                        .padding(top = 1.dp, end = 2.dp)
-                )
-            }
-        }
-        if (showLegalHoliday && holidayBadge != null) {
             Text(
-                text = holidayBadge,
-                color = holidayBadgeColor.copy(alpha = holidayBadgeAlpha),
+                text = shiftLabel,
+                color = shiftAccentColor.copy(alpha = shiftAlpha),
                 fontSize = 9.sp,
                 fontWeight = FontWeight.Bold,
                 lineHeight = 9.sp,
                 modifier = Modifier
                     .align(Alignment.TopEnd)
                     .zIndex(1f)
-                    .background(MaterialTheme.colorScheme.background)
                     .padding(top = 1.dp, end = 2.dp)
-                    .padding(horizontal = 2.dp)
             )
         }
     }