feat: separate open and completed todos into collapsible sections

MindDump/Models/TodoList.swift

@@ -13,6 +13,14 @@ class TodoList: Identifiable {
         items.sorted { $0.createdAt < $1.createdAt }
     }
 
+    var openItems: [TodoItem] {
+        items.filter { !$0.isCompleted }.sorted { $0.createdAt < $1.createdAt }
+    }
+
+    var completedItems: [TodoItem] {
+        items.filter { $0.isCompleted }.sorted { ($0.modifiedAt ?? $0.createdAt) > ($1.modifiedAt ?? $1.createdAt) }
+    }
+
     init(id: UUID = UUID(), name: String, items: [TodoItem] = [], isInbox: Bool = false) {
         self.id = id
         self.name = name

MindDump/Views/ListDetailView.swift

@@ -5,6 +5,7 @@ struct ListDetailView: View {
     let listID: UUID
     @State private var editorItem: TodoItem?
     @State private var moveItem: TodoItem?
+    @State private var showCompleted = true
 
     private var todoList: TodoList? {
         store.lists.first { $0.id == listID }
@@ -13,12 +14,13 @@ struct ListDetailView: View {
     var body: some View {
         Group {
             if let todoList {
-                if todoList.sortedItems.isEmpty {
+                if todoList.items.isEmpty {
                     ContentUnavailableView("Keine Einträge", systemImage: "tray")
                 } else {
                     List {
+                        Section {
                             TodoListView(
-                            items: todoList.sortedItems,
+                                items: todoList.openItems,
                                 onToggle: { item in
                                     store.toggleItemCompleted(item.id, in: listID)
                                 },
@@ -33,6 +35,41 @@ struct ListDetailView: View {
                                 }
                             )
                         }
+
+                        if !todoList.completedItems.isEmpty {
+                            Section {
+                                if showCompleted {
+                                    TodoListView(
+                                        items: todoList.completedItems,
+                                        onToggle: { item in
+                                            store.toggleItemCompleted(item.id, in: listID)
+                                        },
+                                        onTap: { item in
+                                            editorItem = item
+                                        },
+                                        onDelete: { item in
+                                            store.deleteItem(item.id, from: listID)
+                                        },
+                                        onMove: { item in
+                                            moveItem = item
+                                        }
+                                    )
+                                }
+                            } header: {
+                                Button {
+                                    withAnimation {
+                                        showCompleted.toggle()
+                                    }
+                                } label: {
+                                    HStack {
+                                        Text("Erledigt (\(todoList.completedItems.count))")
+                                        Spacer()
+                                        Image(systemName: showCompleted ? "chevron.down" : "chevron.right")
+                                    }
+                                }
+                            }
+                        }
+                    }
                 }
             }
         }