实现结账流程：替换旧归还逻辑为完整结账-修正-争议流程

- 新增 order_checkouts 表，支持结账明细（消耗/押金扣除/退回/号主入账）
- 租客发起结账 → 号主确认 → 已完成（正常路径）
- 号主修改结账 → 租客确认修正 → 已完成（修正路径）
- 结账阶段任一方发起争议 → 后台仲裁 → 已完成/已关闭/异常（争议路径）
- 争议模块适配结账争议类型，仲裁结果新增 mark_abnormal
- 超时任务适配新的 pending_checkout_confirm 状态
- 前端结账明细面板、发起结账/确认/修正/拒绝表单全部实现
- 移除旧的 SubmitReturn/ConfirmReturn 接口

frontend/src/views/admin/AdminAuditLogsView.vue

@@ -96,8 +96,8 @@ function actionType(action: string) {
           <el-option label="订单标记异常" value="order.mark_abnormal" />
           <el-option label="号主交接超时" value="order.timeout.owner_submit" />
           <el-option label="租客确认超时" value="order.timeout.renter_confirm" />
-          <el-option label="租客归还逾期" value="order.timeout.return_overdue" />
-          <el-option label="号主确认归还超时" value="order.timeout.owner_return_confirm" />
+          <el-option label="租客结账逾期" value="order.timeout.return_overdue" />
+          <el-option label="号主确认结账超时" value="order.timeout.owner_checkout_confirm" />
           <el-option label="申诉仲裁" value="dispute.arbitrate" />
           <el-option label="更新系统配置" value="system_config.update" />
           <el-option label="创建系统配置" value="system_config.create" />

frontend/src/views/admin/AdminDashboardView.vue

@@ -86,7 +86,7 @@ function money(value?: number) {
           <strong>{{ dashboard.pending.pending_handoffs }}</strong>
         </div>
         <div class="pending-row">
-          <span>待归还确认</span>
+          <span>待结账确认</span>
           <strong>{{ dashboard.pending.pending_return_confirms }}</strong>
         </div>
       </div>

frontend/src/views/admin/AdminDisputesView.vue

@@ -99,7 +99,7 @@ function readError(error: unknown, fallback: string) {
     <div class="page-header">
       <p class="eyebrow">Arbitration</p>
       <h1>仲裁中心</h1>
-      <p>处理无法登录、资产损失、哈夫币争议和超时归还。</p>
+      <p>处理无法登录、资产损失、哈夫币争议和结账争议。</p>
     </div>
 
     <el-table v-loading="loading" class="table-panel" :data="disputes">
@@ -134,6 +134,7 @@ function readError(error: unknown, fallback: string) {
           <el-option label="释放押金" value="release_deposit" />
           <el-option label="赔付号主" value="compensate_owner" />
           <el-option label="关闭订单" value="order_close" />
+          <el-option label="标记异常" value="mark_abnormal" />
         </el-select>
         <el-input-number
           v-if="['partial_refund', 'deduct_deposit', 'compensate_owner'].includes(result)"

frontend/src/views/admin/AdminOrderDetailView.vue

@@ -121,6 +121,20 @@ function readError(error: unknown, fallback: string) {
       </div>
     </div>
 
+    <div v-if="order?.checkout" class="order-panel dashboard-panel">
+      <h2>结账信息</h2>
+      <div class="detail-grid checkout-grid">
+        <p>结账状态：{{ order.checkout.status }}</p>
+        <p>租金收入：¥{{ order.checkout.rent_amount }}</p>
+        <p>押金：¥{{ order.checkout.deposit_amount }}</p>
+        <p>消耗扣款：¥{{ order.checkout.deposit_deduct_amount }}</p>
+        <p>租客退回：¥{{ order.checkout.renter_refund_amount }}</p>
+        <p>号主入账：¥{{ order.checkout.owner_income_amount }}</p>
+      </div>
+      <p v-if="order.checkout.content">租客说明：{{ order.checkout.content }}</p>
+      <p v-if="order.checkout.owner_adjustment_reason">号主修正：{{ order.checkout.owner_adjustment_reason }}</p>
+    </div>
+
     <div v-if="order" class="order-panel dashboard-panel code-panel">
       <h2>账号快照</h2>
       <pre>{{ snapshotText }}</pre>

frontend/src/views/admin/AdminOrdersView.vue

@@ -39,7 +39,10 @@ async function loadOrders() {
           <el-option label="待交接" value="pending_handoff" />
           <el-option label="使用中" value="renting" />
           <el-option label="逾期中" value="overdue" />
-          <el-option label="待归还确认" value="pending_return_confirm" />
+          <el-option label="待结账确认" value="pending_return_confirm" />
+          <el-option label="待号主确认结账" value="pending_checkout_confirm" />
+          <el-option label="待租客确认修正" value="pending_checkout_accept" />
+          <el-option label="结账争议中" value="checkout_disputing" />
           <el-option label="申诉中" value="disputing" />
           <el-option label="异常" value="abnormal" />
           <el-option label="已完成" value="completed" />