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
+}