refactor(todo): 移除 due_at 字段，改用 order 字段管理象限内顺序

apps/lib/features/todo/data/todo_api.dart

@@ -25,13 +25,13 @@ class TodoApi {
   Future<TodoResponse> createTodo({
     required String title,
     String? description,
-    DateTime? dueAt,
     int priority = 1,
+    int? order,
     List<String> scheduleItemIds = const [],
   }) async {
     final data = <String, dynamic>{'title': title, 'priority': priority};
     if (description != null) data['description'] = description;
-    if (dueAt != null) data['due_at'] = dueAt.toIso8601String();
+    if (order != null) data['order'] = order;
     if (scheduleItemIds.isNotEmpty) data['schedule_item_ids'] = scheduleItemIds;
 
     final response = await _client.post(_prefix, data: data);
@@ -42,16 +42,16 @@ class TodoApi {
     String id, {
     String? title,
     String? description,
-    DateTime? dueAt,
     int? priority,
+    int? order,
     String? status,
     List<String>? scheduleItemIds,
   }) async {
     final data = <String, dynamic>{};
     if (title != null) data['title'] = title;
     if (description != null) data['description'] = description;
-    if (dueAt != null) data['due_at'] = dueAt.toIso8601String();
     if (priority != null) data['priority'] = priority;
+    if (order != null) data['order'] = order;
     if (status != null) data['status'] = status;
     if (scheduleItemIds != null) data['schedule_item_ids'] = scheduleItemIds;
 
@@ -59,12 +59,19 @@ class TodoApi {
     return TodoResponse.fromJson(response.data);
   }
 
-  Future<void> updateTodoPriority(String id, int priority) async {
-    try {
-      await _client.patch('$_prefix/$id', data: {'priority': priority});
-    } catch (_) {
-      // Ignore response parsing errors, just need to know if request succeeded
-    }
+  Future<void> reorderTodos(List<TodoReorderItemPayload> items) async {
+    final data = {
+      'items': items
+          .map(
+            (item) => {
+              'id': item.id,
+              'priority': item.priority,
+              'order': item.order,
+            },
+          )
+          .toList(),
+    };
+    await _client.patch('$_prefix/reorder', data: data);
   }
 
   Future<TodoResponse> completeTodo(String id) async {
@@ -77,6 +84,18 @@ class TodoApi {
   }
 }
 
+class TodoReorderItemPayload {
+  final String id;
+  final int priority;
+  final int order;
+
+  const TodoReorderItemPayload({
+    required this.id,
+    required this.priority,
+    required this.order,
+  });
+}
+
 class ScheduleItemBasic {
   final String id;
   final String title;
@@ -107,7 +126,7 @@ class TodoResponse {
   final String ownerId;
   final String title;
   final String? description;
-  final DateTime? dueAt;
+  final int order;
   final int priority;
   final String status;
   final DateTime? completedAt;
@@ -120,8 +139,8 @@ class TodoResponse {
     required this.ownerId,
     required this.title,
     this.description,
-    this.dueAt,
     required this.priority,
+    required this.order,
     required this.status,
     this.completedAt,
     required this.createdAt,
@@ -136,10 +155,8 @@ class TodoResponse {
       ownerId: json['owner_id'] as String,
       title: json['title'] as String,
       description: json['description'] as String?,
-      dueAt: json['due_at'] != null
-          ? DateTime.parse(json['due_at'] as String)
-          : null,
       priority: json['priority'] as int,
+      order: json['order'] as int,
       status: json['status'] as String,
       completedAt: json['completed_at'] != null
           ? DateTime.parse(json['completed_at'] as String)
@@ -157,8 +174,8 @@ class TodoResponse {
     String? ownerId,
     String? title,
     String? description,
-    DateTime? dueAt,
     int? priority,
+    int? order,
     String? status,
     DateTime? completedAt,
     DateTime? createdAt,
@@ -170,8 +187,8 @@ class TodoResponse {
       ownerId: ownerId ?? this.ownerId,
       title: title ?? this.title,
       description: description ?? this.description,
-      dueAt: dueAt ?? this.dueAt,
       priority: priority ?? this.priority,
+      order: order ?? this.order,
       status: status ?? this.status,
       completedAt: completedAt ?? this.completedAt,
       createdAt: createdAt ?? this.createdAt,