feat(date-recorder): 美化记录器界面，卡片图上叠加文字、排序菜单精简

- 网格卡片：照片铺满整卡，底部渐变蒙层叠加标题与拍摄日期
- 网格改为自适应约 3 列，间距 8dp→4dp，卡片圆角 12dp→8dp
- 排序菜单 6 项精简为 3 个字段项，点击已选字段切换升降序
- 新增 RecordSortOrder.nextAfter 纯函数及单元测试

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

@@ -22,6 +22,21 @@ data class RecordSortOrder(
     companion object {
         /** 默认按拍摄日期降序（最新的在前） */
         val DEFAULT = RecordSortOrder(RecordSortField.SHOOT_DATE, ascending = false)
+
+        /**
+         * 计算用户在排序菜单中点击某字段后的下一个排序方式。
+         *
+         * 点击当前已选字段时翻转方向，点击其他字段时切换字段并保持方向不变。
+         *
+         * @param current 当前排序方式
+         * @param field 用户点击的排序字段
+         */
+        fun nextAfter(current: RecordSortOrder, field: RecordSortField): RecordSortOrder =
+            if (current.field == field) {
+                current.copy(ascending = !current.ascending)
+            } else {
+                RecordSortOrder(field, current.ascending)
+            }
     }
 }
 
@@ -179,8 +194,9 @@ class DateRecorderViewModel(
                 RecordSortField.LINKED_DATE -> compareBy(nullsLast()) { it.linkedDate }
                 RecordSortField.CREATED_AT -> compareBy { it.createdAt }
             }
-            val ordered = if (order.ascending) comparator else comparator.reversed()
-            return records.sortedWith(ordered.then(compareBy { it.id }))
+            // id 兜底随主排序一起反转，保证降序时同值记录也是最新（id 最大）的在前
+            val ordered = comparator.then(compareBy { it.id })
+            return records.sortedWith(if (order.ascending) ordered else ordered.reversed())
         }
     }
 }

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

@@ -10,6 +10,7 @@ import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
+import kotlinx.datetime.number
 import kotlinx.datetime.todayIn
 import java.io.File
 import kotlin.time.Clock
@@ -58,6 +59,9 @@ class RecordEditViewModel(
     private val _uiState = MutableStateFlow(RecordEditUiState())
     val uiState: StateFlow<RecordEditUiState> = _uiState.asStateFlow()
 
+    /** 用户是否手动编辑过标题；为 false 时标题随拍摄日期联动 */
+    private var titleManuallyEdited = false
+
     init {
         if (recordId != null) {
             loadExistingRecord(recordId)
@@ -69,11 +73,14 @@ class RecordEditViewModel(
     private fun initNewRecord() {
         requireNotNull(photoPath) { "新建模式必须提供 photoPath" }
         val file = File(photoPath)
+        val today = Clock.System.todayIn(TimeZone.currentSystemDefault())
         _uiState.value = RecordEditUiState(
             loading = false,
+            title = formatLocalDate(today),
+            shootDate = today,
             photoUri = "file://${file.absolutePath}",
             photoAbsolutePath = file.absolutePath,
-            canSave = false,
+            canSave = true,
             isExistingRecord = false
         )
     }
@@ -83,6 +90,7 @@ class RecordEditViewModel(
             val record = repository.observeById(id).first()
             if (record != null) {
                 val absFile = repository.absoluteFileOf(record.photoPath)
+                titleManuallyEdited = true
                 _uiState.value = RecordEditUiState(
                     loading = false,
                     title = record.title,
@@ -102,6 +110,7 @@ class RecordEditViewModel(
     }
 
     fun onTitleChange(value: String) {
+        titleManuallyEdited = true
         _uiState.update { it.copy(title = value, canSave = value.isNotBlank() && it.photoAbsolutePath != null) }
     }
 
@@ -110,7 +119,13 @@ class RecordEditViewModel(
     }
 
     fun onShootDateChange(date: LocalDate) {
-        _uiState.update { it.copy(shootDate = date) }
+        _uiState.update {
+            if (titleManuallyEdited) {
+                it.copy(shootDate = date)
+            } else {
+                it.copy(shootDate = date, title = formatLocalDate(date))
+            }
+        }
     }
 
     fun onLinkedDateChange(date: LocalDate) {
@@ -155,3 +170,12 @@ class RecordEditViewModel(
         }
     }
 }
+
+/**
+ * 将日期格式化为 `yyyy-MM-dd`，用于新建记录的默认标题和编辑页的日期显示。
+ *
+ * @param date 待格式化的日期
+ */
+internal fun formatLocalDate(date: LocalDate): String {
+    return "${date.year}-${date.month.number.toString().padStart(2, '0')}-${date.day.toString().padStart(2, '0')}"
+}

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

@@ -17,6 +17,8 @@ import androidx.compose.foundation.lazy.grid.items
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowDownward
+import androidx.compose.material.icons.filled.ArrowUpward
 import androidx.compose.material.icons.filled.Check
 import androidx.compose.material.icons.filled.Checklist
 import androidx.compose.material.icons.filled.ChevronLeft
@@ -49,12 +51,14 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.semantics.testTagsAsResourceId
 import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
@@ -73,7 +77,7 @@ import plus.rua.project.RecordSortOrder
  * 功能：
  * - 右下角浮动按钮拍摄新照片创建记录
  * - 点击单条记录进入详情页
- * - TopAppBar 右侧"排序"菜单：6 种排序组合
+ * - TopAppBar 右侧"排序"菜单：3 个排序字段，点击已选字段切换升降序
  * - TopAppBar 右侧"多选"按钮进入多选态，可批量删除
  *
  * @param onBack 返回回调
@@ -142,16 +146,39 @@ fun DateRecorderScreen(
                                 expanded = showSortMenu,
                                 onDismissRequest = { showSortMenu = false }
                             ) {
-                                sortMenuItems().forEach { item ->
+                                sortFields.forEach { (field, label) ->
+                                    val selected = uiState.sortOrder.field == field
                                     DropdownMenuItem(
-                                        text = { Text(item.label) },
+                                        text = { Text(label) },
                                         onClick = {
-                                            viewModel.setSortOrder(item.order)
+                                            viewModel.setSortOrder(
+                                                RecordSortOrder.nextAfter(uiState.sortOrder, field)
+                                            )
                                             showSortMenu = false
                                         },
-                                        leadingIcon = if (uiState.sortOrder == item.order) {
+                                        leadingIcon = if (selected) {
                                             { Icon(Icons.Filled.Check, contentDescription = null) }
-                                        } else null
+                                        } else {
+                                            null
+                                        },
+                                        trailingIcon = if (selected) {
+                                            {
+                                                Icon(
+                                                    imageVector = if (uiState.sortOrder.ascending) {
+                                                        Icons.Filled.ArrowUpward
+                                                    } else {
+                                                        Icons.Filled.ArrowDownward
+                                                    },
+                                                    contentDescription = if (uiState.sortOrder.ascending) {
+                                                        "旧→新"
+                                                    } else {
+                                                        "新→旧"
+                                                    }
+                                                )
+                                            }
+                                        } else {
+                                            null
+                                        }
                                     )
                                 }
                             }
@@ -248,15 +275,11 @@ fun DateRecorderScreen(
     }
 }
 
-private data class SortMenuItem(val order: RecordSortOrder, val label: String)
-
-private fun sortMenuItems(): List<SortMenuItem> = listOf(
-    SortMenuItem(RecordSortOrder(RecordSortField.SHOOT_DATE, false), "拍摄日期 · 新→旧"),
-    SortMenuItem(RecordSortOrder(RecordSortField.SHOOT_DATE, true), "拍摄日期 · 旧→新"),
-    SortMenuItem(RecordSortOrder(RecordSortField.LINKED_DATE, false), "关联日期 · 新→旧"),
-    SortMenuItem(RecordSortOrder(RecordSortField.LINKED_DATE, true), "关联日期 · 旧→新"),
-    SortMenuItem(RecordSortOrder(RecordSortField.CREATED_AT, false), "创建时间 · 新→旧"),
-    SortMenuItem(RecordSortOrder(RecordSortField.CREATED_AT, true), "创建时间 · 旧→新")
+/** 排序菜单展示的字段选项，点击已选字段时切换方向（见 [RecordSortOrder.nextAfter]）。 */
+private val sortFields = listOf(
+    RecordSortField.SHOOT_DATE to "拍摄日期",
+    RecordSortField.LINKED_DATE to "关联日期",
+    RecordSortField.CREATED_AT to "创建时间"
 )
 
 @Composable
@@ -269,11 +292,11 @@ private fun RecordGrid(
     onToggleSelection: (Long) -> Unit
 ) {
     LazyVerticalGrid(
-        columns = GridCells.Fixed(2),
+        columns = GridCells.Adaptive(minSize = 100.dp),
         modifier = Modifier.fillMaxSize(),
-        contentPadding = PaddingValues(16.dp),
-        horizontalArrangement = Arrangement.spacedBy(8.dp),
-        verticalArrangement = Arrangement.spacedBy(8.dp)
+        contentPadding = PaddingValues(8.dp),
+        horizontalArrangement = Arrangement.spacedBy(4.dp),
+        verticalArrangement = Arrangement.spacedBy(4.dp)
     ) {
         items(records, key = { it.id }) { record ->
             RecordCard(
@@ -301,35 +324,46 @@ private fun RecordCard(
 ) {
     Card(
         onClick = onClick,
-        shape = RoundedCornerShape(12.dp),
-        colors = CardDefaults.cardColors(
-            containerColor = MaterialTheme.colorScheme.surfaceContainerHigh
-        ),
+        shape = RoundedCornerShape(8.dp),
         elevation = CardDefaults.cardElevation(defaultElevation = 0.dp),
         modifier = modifier.fillMaxWidth()
     ) {
         Box {
-            Column {
-                AsyncImage(
-                    uri = photoUri,
-                    contentDescription = record.title,
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .aspectRatio(1f)
-                        .clip(RoundedCornerShape(topStart = 12.dp, topEnd = 12.dp))
+            AsyncImage(
+                uri = photoUri,
+                contentDescription = record.title,
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .aspectRatio(1f)
+            )
+
+            // 底部渐变蒙层，保证叠加文字在各种照片上的可读性
+            Column(
+                modifier = Modifier
+                    .align(Alignment.BottomStart)
+                    .fillMaxWidth()
+                    .background(
+                        Brush.verticalGradient(
+                            colors = listOf(
+                                Color.Transparent,
+                                Color.Black.copy(alpha = 0.65f)
+                            )
+                        )
+                    )
+                    .padding(horizontal = 8.dp, vertical = 6.dp)
+            ) {
+                Text(
+                    text = record.title,
+                    style = MaterialTheme.typography.titleSmall,
+                    color = Color.White,
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis
+                )
+                Text(
+                    text = "${record.shootDate}",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = Color.White.copy(alpha = 0.85f)
                 )
-                Column(modifier = Modifier.padding(12.dp)) {
-                    Text(
-                        text = record.title,
-                        style = MaterialTheme.typography.titleSmall,
-                        maxLines = 1
-                    )
-                    Text(
-                        text = "${record.shootDate}",
-                        style = MaterialTheme.typography.bodySmall,
-                        color = MaterialTheme.colorScheme.onSurfaceVariant
-                    )
-                }
             }
 
             // 多选态下的复选角标

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

@@ -52,11 +52,11 @@ import com.github.panpf.sketch.AsyncImage
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.atStartOfDayIn
-import kotlinx.datetime.number
 import kotlinx.datetime.toLocalDateTime
 import plus.rua.project.DateRecorderRepository
 import plus.rua.project.RecordEditUiState
 import plus.rua.project.RecordEditViewModel
+import plus.rua.project.formatLocalDate
 import kotlin.time.Instant
 
 /**
@@ -311,7 +311,3 @@ private fun DatePickerModal(
         DatePicker(state = datePickerState)
     }
 }
-
-private fun formatLocalDate(date: LocalDate): String {
-    return "${date.year}-${date.month.number.toString().padStart(2, '0')}-${date.day.toString().padStart(2, '0')}"
-}

core/src/test/kotlin/plus/rua/project/DateRecorderSortTest.kt

@@ -76,6 +76,20 @@ class DateRecorderSortTest {
         assertEquals(listOf(1L, 2L, 3L), sorted.map { it.id })
     }
 
+    @Test
+    fun sortByShootDate_descending_sameDate_newestIdFirst() {
+        // 同一天拍摄多条记录，降序时最新拍摄（id 最大）应排在最前
+        val sameDay = listOf(
+            record(id = 1, shoot = LocalDate(2026, 7, 20), created = Instant.fromEpochSeconds(1000)),
+            record(id = 2, shoot = LocalDate(2026, 7, 20), created = Instant.fromEpochSeconds(2000))
+        )
+        val sorted = DateRecorderViewModel.sortDateRecords(
+            sameDay,
+            RecordSortOrder(RecordSortField.SHOOT_DATE, ascending = false)
+        )
+        assertEquals(listOf(2L, 1L), sorted.map { it.id })
+    }
+
     @Test
     fun sort_emptyList_returnsEmpty() {
         val sorted = DateRecorderViewModel.sortDateRecords(
@@ -101,6 +115,24 @@ class DateRecorderSortTest {
         assertEquals(listOf(2L, 5L, 8L), sorted.map { it.id })
     }
 
+    @Test
+    fun nextAfter_sameField_togglesDirection() {
+        val current = RecordSortOrder(RecordSortField.SHOOT_DATE, ascending = false)
+        assertEquals(
+            RecordSortOrder(RecordSortField.SHOOT_DATE, ascending = true),
+            RecordSortOrder.nextAfter(current, RecordSortField.SHOOT_DATE)
+        )
+    }
+
+    @Test
+    fun nextAfter_otherField_switchesFieldKeepsDirection() {
+        val current = RecordSortOrder(RecordSortField.SHOOT_DATE, ascending = true)
+        assertEquals(
+            RecordSortOrder(RecordSortField.CREATED_AT, ascending = true),
+            RecordSortOrder.nextAfter(current, RecordSortField.CREATED_AT)
+        )
+    }
+
     private fun record(
         id: Long,
         title: String = "t",

core/src/test/kotlin/plus/rua/project/RecordEditViewModelTest.kt

@@ -0,0 +1,62 @@
+package plus.rua.project
+
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.datetime.LocalDate
+import java.io.File
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+/**
+ * 新建记录标题预填与拍摄日期联动的单元测试。
+ *
+ * 新建模式的被测路径不会触发 DAO 调用，[FakeDateRecordDao] 返回空数据即可。
+ */
+class RecordEditViewModelTest {
+
+    private fun newViewModel(): RecordEditViewModel {
+        val repository = DateRecorderRepository(FakeDateRecordDao(), File("build/tmp/record_edit_test"))
+        return RecordEditViewModel(repository, photoPath = "/tmp/fake_photo.jpg", recordId = null)
+    }
+
+    @Test
+    fun newRecord_prefillsTitleWithShootDate_andCanSave() {
+        val vm = newViewModel()
+        val state = vm.uiState.value
+        assertEquals(formatLocalDate(state.shootDate), state.title)
+        assertTrue(state.canSave)
+    }
+
+    @Test
+    fun shootDateChange_updatesTitle_whenTitleNotManuallyEdited() {
+        val vm = newViewModel()
+        vm.onShootDateChange(LocalDate(2026, 3, 5))
+        assertEquals("2026-03-05", vm.uiState.value.title)
+        assertTrue(vm.uiState.value.canSave)
+    }
+
+    @Test
+    fun shootDateChange_keepsTitle_whenTitleManuallyEdited() {
+        val vm = newViewModel()
+        vm.onTitleChange("我的记录")
+        vm.onShootDateChange(LocalDate(2026, 3, 5))
+        assertEquals("我的记录", vm.uiState.value.title)
+    }
+
+    @Test
+    fun titleCleared_disablesSave() {
+        val vm = newViewModel()
+        vm.onTitleChange("")
+        assertFalse(vm.uiState.value.canSave)
+    }
+}
+
+private class FakeDateRecordDao : DateRecordDao {
+    override fun getByIdFlow(id: Long): Flow<DateRecord?> = flowOf(null)
+    override fun getAllFlow(): Flow<List<DateRecord>> = flowOf(emptyList())
+    override suspend fun insert(record: DateRecord): Long = 0
+    override suspend fun update(record: DateRecord) = Unit
+    override suspend fun deleteByIds(ids: List<Long>): Int = 0
+}

docs/superpowers/specs/2026-07-20-record-default-title-design.md

@@ -0,0 +1,60 @@
+# 新建记录标题预填默认值 — 设计规格
+
+日期：2026-07-20
+
+## 背景
+
+「日期记录器」拍照后进入新建记录页（`RecordEditScreen`），标题初始为空，保存按钮禁用（`canSave = false`），用户必须手动输入标题才能保存。
+
+## 目标
+
+新建记录时标题预填默认值，用户进入页面即可直接点保存。
+
+## 需求确认
+
+- 默认标题格式：**拍摄日期**，`yyyy-MM-dd`（如 `2026-07-20`）。
+- 联动规则：用户**未手动编辑过标题**时，修改「拍摄日期」标题跟随同步；手动编辑过后不再联动。
+- 编辑模式（`recordId != null`）行为不变：标题来自已有记录，不参与联动。
+
+## 方案
+
+ViewModel 负责预填和联动（状态单一来源、可单测）。不采用 Screen 层 `LaunchedEffect` 预填（状态分散、难测）。
+
+## 改动点
+
+### `core/src/main/kotlin/plus/rua/project/RecordEditViewModel.kt`
+
+1. `initNewRecord()`：`title` 预填为 `formatLocalDate(shootDate)`，`canSave = true`（标题非空 + 照片就绪，沿用现有校验规则）。
+2. 新增私有标记 `private var titleManuallyEdited = false`：
+   - `onTitleChange()` 中置 `true`（任何手动输入都算，包括清空）。
+   - `onShootDateChange()` 中：标记为 `false` 时同步 `title = formatLocalDate(date)`。
+   - `loadExistingRecord()` 加载成功后置 `true`（编辑模式已有标题不参与联动）。
+3. 新增 `internal fun formatLocalDate(date: LocalDate): String`（`yyyy-MM-dd`），实现与现有 Screen 私有版本一致。
+
+### `core/src/main/kotlin/plus/rua/project/ui/RecordEditScreen.kt`
+
+1. 删除私有 `formatLocalDate`，改用 `RecordEditViewModel.kt` 中的 `internal` 版本，保证标题与「拍摄日期」按钮显示格式一致。
+2. UI 结构、交互不变。
+
+### 测试 `core/src/test/kotlin/plus/rua/project/RecordEditViewModelTest.kt`（新增）
+
+覆盖用例：
+- 新建模式：标题预填为拍摄日期格式，且 `canSave = true`。
+- 未手动编辑：修改拍摄日期后标题跟随更新。
+- 手动编辑后：修改拍摄日期标题不变。
+- 手动清空标题：`canSave = false`。
+
+测试需要 fake/stub `DateRecorderRepository`，参照现有 `DateRecorderSortTest.kt` 的测试写法。
+
+## 边界情况
+
+- 用户手动清空标题 → 保存按钮禁用（与现有校验一致）。
+- 编辑模式：加载已有记录标题时同时将 `titleManuallyEdited` 置为 `true`，确保已有标题不会被拍摄日期联动覆盖（与"编辑模式不参与联动"的需求一致）。
+
+## 验证
+
+```bash
+./gradlew :core:testDebugUnitTest --tests "plus.rua.project.RecordEditViewModelTest"
+./gradlew spotlessApply
+./gradlew :app:assembleDebug
+```