feat(distribution): 补齐退款加价回退、本站自卖与开通默认规则

退款时压缩卖方加价，人工/自动批次仅完结单可入账，号主收入进主站钱包；仲裁后重算释放并支持作废未入账 DS。开通时四种模式按默认生效，对外口径合并为 35/40/25，不再单独展示通道费。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/features/admin/views/AdminDistributionSitesView.vue

@@ -63,9 +63,6 @@ const onboardForm = reactive({
   admin_password: '',
   admin_nickname: '',
   member_type: 'operator',
-  distributor_receive_ratio: 35,
-  platform_sell_ratio: 40,
-  service_fee_value: 25,
   settlement_hold_days: 7,
   display_account_enabled: true,
   tax_enabled: false,
@@ -105,9 +102,6 @@ function handleOpenOnboard() {
   onboardForm.admin_password = ''
   onboardForm.admin_nickname = ''
   onboardForm.member_type = 'operator'
-  onboardForm.distributor_receive_ratio = 35
-  onboardForm.platform_sell_ratio = 40
-  onboardForm.service_fee_value = 25
   onboardForm.settlement_hold_days = 7
   onboardForm.display_account_enabled = true
   onboardForm.tax_enabled = false
@@ -129,9 +123,6 @@ async function handleOnboardSubmit() {
         admin_password: onboardForm.admin_password,
         admin_nickname: onboardForm.admin_nickname.trim() || undefined,
         member_type: onboardForm.member_type,
-        distributor_receive_ratio: Number(onboardForm.distributor_receive_ratio),
-        platform_sell_ratio: Number(onboardForm.platform_sell_ratio),
-        service_fee_value: Number(onboardForm.service_fee_value),
         settlement_hold_days: Number(onboardForm.settlement_hold_days),
         display_account_enabled: onboardForm.display_account_enabled,
         tax_enabled: onboardForm.tax_enabled,
@@ -189,8 +180,7 @@ onMounted(() => {
       <div>
         <h2 class="page-title">分销站点管理</h2>
         <p class="page-subtitle">
-          开通分销站、配置结算冷却期。利润按 35% 收号 / 40% 卖出 / 25%
-          服务费切分，通道费由主站承担。
+          开通分销站、配置结算冷却期。利润按 35% 收号 / 40% 卖出 / 25% 服务费切分。
         </p>
       </div>
       <div class="header-actions">
@@ -325,50 +315,15 @@ onMounted(() => {
           </el-col>
         </el-row>
 
-        <div class="form-section-title">3. 分站收号规则与冷却期</div>
+        <div class="form-section-title">3. 结算冷却期与展示</div>
         <el-alert
           type="info"
           :closable="false"
           show-icon
-          title="此处只生成「两方 · 分站收号」草稿。利润 = 净付款 − 号主 − 加价；通道费 0.5% 由主站承担。另外两种模式请到规则页按全局默认启用或单独配置。"
+          title="开通后四种分成模式均按默认生效：收号 35% / 卖出 40% / 服务费 25%（本站自卖为 75% + 25%）。之后可在「分销规则」页单独调整。"
           style="margin-bottom: 12px"
         />
         <el-row :gutter="16">
-          <el-col :span="12">
-            <el-form-item label="分站收号分成 (%)">
-              <el-input-number
-                v-model="onboardForm.distributor_receive_ratio"
-                :min="0"
-                :max="100"
-                :step="0.1"
-                style="width: 100%"
-              />
-            </el-form-item>
-          </el-col>
-          <el-col :span="12">
-            <el-form-item label="主站卖出分成 (%)">
-              <el-input-number
-                v-model="onboardForm.platform_sell_ratio"
-                :min="0"
-                :max="100"
-                :step="0.1"
-                style="width: 100%"
-              />
-            </el-form-item>
-          </el-col>
-        </el-row>
-        <el-row :gutter="16">
-          <el-col :span="12">
-            <el-form-item label="平台服务费 (%)">
-              <el-input-number
-                v-model="onboardForm.service_fee_value"
-                :min="0"
-                :max="100"
-                :step="1"
-                style="width: 100%"
-              />
-            </el-form-item>
-          </el-col>
           <el-col :span="12">
             <el-form-item label="结算冷却期 (天)">
               <el-input-number
@@ -380,19 +335,15 @@ onMounted(() => {
               />
             </el-form-item>
           </el-col>
-        </el-row>
-        <el-row :gutter="16">
           <el-col :span="12">
             <el-form-item label="展示主站账号">
               <el-switch v-model="onboardForm.display_account_enabled" />
             </el-form-item>
           </el-col>
-          <el-col :span="12">
-            <el-form-item label="是否征税">
-              <el-switch v-model="onboardForm.tax_enabled" />
-            </el-form-item>
-          </el-col>
         </el-row>
+        <el-form-item label="是否征税">
+          <el-switch v-model="onboardForm.tax_enabled" />
+        </el-form-item>
       </el-form>
       <template #footer>
         <el-button @click="onboardDialogVisible = false">取消</el-button>
@@ -425,10 +376,9 @@ onMounted(() => {
           <el-descriptions-item label="分销后台地址">
             <code>http://{{ windowHost }}:5190/login</code>
           </el-descriptions-item>
-          <el-descriptions-item label="初始规则">
-            分站收号 {{ onboardResult.rule.distributor_receive_ratio }}% · 主站卖出
-            {{ onboardResult.rule.platform_sell_ratio }}% · 服务费
-            {{ onboardResult.rule.service_fee_value }}%（草稿，通道费主站承担）
+          <el-descriptions-item label="初始分成规则">
+            四种模式均已按默认生效：收号 35% / 卖出 40% / 服务费 25%（本站自卖 75% +
+            25%），可到规则页调整。
           </el-descriptions-item>
           <el-descriptions-item label="结算冷却期">
             {{ onboardResult.site.settlement_hold_days }} 天