fix(payment): 充值商品选项旧字符串值导致假条目且不可删除

- SchemaProvider 读取时 group/repeater 字段忽略非数组旧值（textarea 时代的
  字符串），回退默认数组，避免前端按字符渲染出 20+ 条假条目
- AksField group/repeater 渲染改为数组安全视图（非数组一律按空列表）
- 充值商品选项默认条数调整为 3 条（PHP 与前端 schema 同步）

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

@@ -507,7 +507,7 @@
     <!-- Repeater (array of objects) — inline expand (default) -->
     <div v-else-if="(schema.type === 'repeater' || schema.type === 'group') && schema.ui !== 'list-modal'" class="aksrt-field__repeater">
       <div
-        v-for="(item, index) in (modelValue || [])"
+        v-for="(item, index) in repeaterItems"
         :key="item._id || index"
         class="aksrt-field__repeater-item"
       >
@@ -548,9 +548,9 @@
 
     <!-- Repeater list-modal: compact list + modal editor -->
     <div v-else-if="(schema.type === 'repeater' || schema.type === 'group') && schema.ui === 'list-modal'" class="aksrt-field__repeater aksrt-field__repeater--list-modal">
-      <div v-if="(modelValue || []).length" class="aksrt-field__repeater-list">
+      <div v-if="repeaterItems.length" class="aksrt-field__repeater-list">
         <div
-          v-for="(item, index) in (modelValue || [])"
+          v-for="(item, index) in repeaterItems"
           :key="item._id || index"
           class="aksrt-field__repeater-list-item"
         >
@@ -565,7 +565,7 @@
               <FaIcon icon="fa fas fa-arrow-up" :size="12" />
             </n-button>
             <n-button
-              v-if="index < (modelValue || []).length - 1"
+              v-if="index < repeaterItems.length - 1"
               size="tiny"
               quaternary
               :disabled="schema.disabled"
@@ -708,6 +708,8 @@ function toggleSecretClear() {
 }
 
 const repeaterLength = computed(() => Array.isArray(props.modelValue) ? props.modelValue.length : 0)
+/** 数组安全视图：非数组（如旧版字符串值）一律按空列表渲染，避免逐字符假条目。 */
+const repeaterItems = computed(() => Array.isArray(props.modelValue) ? props.modelValue : [])
 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))
 
@@ -1083,7 +1085,7 @@ function openRepeaterModal(index) {
   if (index < 0 && reachedRepeaterMaximum.value) return
   if (props.schema.disabled) return
   if (index >= 0) {
-    const item = (props.modelValue || [])[index] || {}
+    const item = (Array.isArray(props.modelValue) ? props.modelValue : [])[index] || {}
     repeaterDraft.value = { ...createRepeaterItem(), ...item }
     repeaterEditingIndex.value = index
   } else {

assets/admin/src/schema/sections/payment/recharge.js

@@ -18,7 +18,6 @@ export const rechargeSchema = {
       { price: 50, pay_price: 0, tag: '', tag_class: '' },
       { price: 100, pay_price: 98, tag: '', tag_class: '' },
       { price: 200, pay_price: 188, tag: '推荐', tag_class: 'jb-cyan' },
-      { price: 500, pay_price: 468, tag: '特惠', tag_class: 'jb-pink' },
     ],
     pay_balance_product_custom_s: true,
     pay_balance_product_custom_limit: 9999,
@@ -94,7 +93,6 @@ export const rechargeSchema = {
             { price: 50, pay_price: 0, tag: '', tag_class: '' },
             { price: 100, pay_price: 98, tag: '', tag_class: '' },
             { price: 200, pay_price: 188, tag: '推荐', tag_class: 'jb-cyan' },
-            { price: 500, pay_price: 468, tag: '特惠', tag_class: 'jb-pink' },
           ],
           help: '用户充值时候，可快速选择的充值金额，同时支持设置折扣',
           fields: [