feat(payment): 新增「售后策略」配置与前台售后弹窗链路

- 后台「支付&付费 → 售后策略」：售后功能开关、申请时效、超时效提示(HTML)、
  预置原因、申请售后说明、所需材料、申请说明占位文案、可上传图片开关；
  PHP schema 与 SPA schema 1:1 对齐，group 字段支持拖拽排序
- PaymentRuntime 新增售后设置解析（缺键回退 schema 默认、HTML 走 kses、
  中文原因稳定 slug）与 after_sale_expired 时效判定（支付时间起算）
- 售后工单支持举证图片（order_aftersale.images 列，最多 3 张，
  复用评论图片上传校验）与上传路由；订单视图模型输出 after_sale 按钮状态
- 前台申请 / 超时效提示 / 售后详细三个独立弹窗（modal-mini + 蓝色炫彩头），
  订单详情弹窗不再内嵌售后表单并清理相关死代码
- 新增 after-sale-policy 契约测试与运行时 harness，527 项契约测试通过

assets/admin/src/components/form/AksField.vue

@@ -507,38 +507,47 @@
       </div>
     </div>
 
-    <!-- Repeater (array of objects) — inline expand (default) -->
+    <!-- Repeater (array of objects) — inline expand (default, draggable) -->
     <div v-else-if="(schema.type === 'repeater' || schema.type === 'group') && schema.ui !== 'list-modal'" class="aksrt-field__repeater">
-      <div
-        v-for="(item, index) in repeaterItems"
-        :key="item._id || index"
-        class="aksrt-field__repeater-item"
+      <draggable
+        v-model="repeaterDragList"
+        :item-key="repeaterDragKey"
+        handle=".aksrt-field__repeater-handle"
+        ghost-class="aksrt-field__repeater-ghost"
+        animation="180"
       >
-        <div class="aksrt-field__repeater-header">
-          <span class="aksrt-field__repeater-index">#{{ index + 1 }}</span>
-          <n-button
-            size="tiny"
-            type="error"
-            text
-            :disabled="schema.disabled || reachedRepeaterMinimum"
-            @click="removeRepeaterItem(index)"
-          >
-            <FaIcon icon="fa fas fa-trash-alt" :size="12" />
-          </n-button>
-        </div>
-        <div class="aksrt-field__repeater-fields">
-          <template v-for="field in (schema.fields || [])" :key="field.key">
-            <AksField
-              v-if="matchDependency(field.dependsOn, item)"
-              :schema="field"
-              :model-value="item[field.key]"
-              :form-data="formData"
-              :disabled="schema.disabled"
-              @update:model-value="updateRepeaterItem(index, field.key, $event)"
-            />
-          </template>
-        </div>
-      </div>
+        <template #item="{ element, index }">
+          <div class="aksrt-field__repeater-item">
+            <div class="aksrt-field__repeater-header">
+              <div class="aksrt-field__repeater-title">
+                <i class="fa fas fa-grip-vertical aksrt-field__repeater-handle" aria-hidden="true"></i>
+                <span class="aksrt-field__repeater-index">#{{ index + 1 }}</span>
+              </div>
+              <n-button
+                size="tiny"
+                type="error"
+                text
+                :disabled="schema.disabled || reachedRepeaterMinimum"
+                @click="removeRepeaterItem(index)"
+              >
+                <FaIcon icon="fa fas fa-trash-alt" :size="12" />
+              </n-button>
+            </div>
+            <div class="aksrt-field__repeater-fields">
+              <template v-for="field in (schema.fields || [])" :key="field.key">
+                <AksField
+                  v-if="matchDependency(field.dependsOn, element)"
+                  :schema="field"
+                  :model-value="element[field.key]"
+                  :form-data="formData"
+                  :disabled="schema.disabled"
+                  @update:model-value="updateRepeaterItem(index, field.key, $event)"
+                />
+              </template>
+            </div>
+          </div>
+        </template>
+      </draggable>
       <n-button
         size="small"
         dashed
@@ -688,6 +697,7 @@ import FaIconPicker from './FaIconPicker.vue'
 import AksMediaField from './AksMediaField.vue'
 import AksGalleryField from './AksGalleryField.vue'
 import AksCodeEditor from './AksCodeEditor.vue'
+import draggable from 'vuedraggable'
 import api from '@/api'
 
 const props = defineProps({
@@ -720,6 +730,31 @@ const repeaterItems = computed(() => Array.isArray(props.modelValue) ? props.mod
 const reachedRepeaterMinimum = computed(() => repeaterLength.value <= Number(props.schema.min || 0))
 const reachedRepeaterMaximum = computed(() => Number(props.schema.max || 0) > 0 && repeaterLength.value >= Number(props.schema.max))
 
+/** 拖拽视图：vuedraggable 以 modelValue 模式工作（内部复制后回传 update:modelValue）。 */
+const repeaterDragList = computed({
+  get: () => (Array.isArray(props.modelValue) ? props.modelValue : []),
+  set: (value) => emit('update:modelValue', Array.isArray(value) ? value : []),
+})
+
+/**
+ * 行 key：优先用行自身 _id；服务端历史数据没有 _id 时按对象引用派生稳定 key，
+ * 避免每次输入都重算 key 导致子字段重挂载、输入焦点丢失。
+ */
+const dragRowKeys = new WeakMap()
+let dragRowKeySeed = 0
+function repeaterDragKey(item) {
+  if (item && typeof item === 'object') {
+    if (item._id) return item._id
+    let key = dragRowKeys.get(item)
+    if (!key) {
+      key = `rpt_drag_${++dragRowKeySeed}`
+      dragRowKeys.set(item, key)
+    }
+    return key
+  }
+  return String(item)
+}
+
 function fieldsetValue(field) {
   const current = props.modelValue && typeof props.modelValue === 'object' && !Array.isArray(props.modelValue)
     ? props.modelValue
@@ -1431,9 +1466,27 @@ function confirmRepeaterModal() {
   display: flex;
   align-items: center;
   justify-content: space-between;
+  gap: 8px;
   margin-bottom: 8px;
 }
 
+.aksrt-field__repeater-title {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  min-width: 0;
+}
+
+.aksrt-field__repeater-handle {
+  cursor: grab;
+  color: var(--aksrt-color-text-tertiary);
+}
+
+.aksrt-field__repeater-ghost {
+  opacity: 0.45;
+  border-color: var(--aksrt-color-primary);
+}
+
 .aksrt-field__repeater-index {
   font-size: 12px;
   font-weight: 600;