feat: define board detail domain and mutation contracts

app/src/main/java/space/hackenslacker/kanbn4droid/app/boarddetail/BoardDetailModels.kt

@@ -0,0 +1,38 @@
+package space.hackenslacker.kanbn4droid.app.boarddetail
+
+data class BoardDetail(
+    val id: String,
+    val title: String,
+    val lists: List<BoardListDetail>,
+)
+
+data class BoardListDetail(
+    val id: String,
+    val title: String,
+    val cards: List<BoardCardSummary>,
+)
+
+data class BoardCardSummary(
+    val id: String,
+    val title: String,
+    val tags: List<BoardTagSummary>,
+    val dueAtEpochMillis: Long?,
+)
+
+data class BoardTagSummary(
+    val id: String,
+    val name: String,
+    val colorHex: String,
+)
+
+sealed interface CardBatchMutationResult {
+    data object Success : CardBatchMutationResult
+    data class PartialSuccess(
+        val failedCardIds: Set<String>,
+        val message: String,
+    ) : CardBatchMutationResult
+
+    data class Failure(
+        val message: String,
+    ) : CardBatchMutationResult
+}

app/src/test/java/space/hackenslacker/kanbn4droid/app/boarddetail/BoardDetailModelsTest.kt

@@ -0,0 +1,58 @@
+package space.hackenslacker.kanbn4droid.app.boarddetail
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+
+class BoardDetailModelsTest {
+
+    @Test
+    fun boardDetailModelsExposeRequiredFields() {
+        val tag = BoardTagSummary(
+            id = "tag-1",
+            name = "Urgent",
+            colorHex = "#FF0000",
+        )
+        val card = BoardCardSummary(
+            id = "card-1",
+            title = "Fix sync bug",
+            tags = listOf(tag),
+            dueAtEpochMillis = null,
+        )
+        val list = BoardListDetail(
+            id = "list-1",
+            title = "To Do",
+            cards = listOf(card),
+        )
+        val detail = BoardDetail(
+            id = "board-1",
+            title = "Sprint",
+            lists = listOf(list),
+        )
+
+        assertEquals("tag-1", tag.id)
+        assertEquals("Urgent", tag.name)
+        assertEquals("#FF0000", tag.colorHex)
+        assertEquals("card-1", card.id)
+        assertEquals("Fix sync bug", card.title)
+        assertEquals(listOf(tag), card.tags)
+        assertNull(card.dueAtEpochMillis)
+        assertEquals("list-1", list.id)
+        assertEquals("To Do", list.title)
+        assertEquals(listOf(card), list.cards)
+        assertEquals("board-1", detail.id)
+        assertEquals("Sprint", detail.title)
+        assertEquals(listOf(list), detail.lists)
+    }
+
+    @Test
+    fun partialSuccessCarriesFailedCardIds() {
+        val result = CardBatchMutationResult.PartialSuccess(
+            failedCardIds = setOf("card-2", "card-9"),
+            message = "Some cards could not be updated.",
+        )
+
+        assertEquals(setOf("card-2", "card-9"), result.failedCardIds)
+        assertEquals("Some cards could not be updated.", result.message)
+    }
+}