feat(distribution): 分站可下调收号比例且不超过主站上限

让分销站能按自身能力下调收号比例扩大利润，同时把主站回收比例作为硬边界，避免分站把比例加得比主站更高。

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

distribution-admin/src/pages/SiteSettings.tsx

@@ -8,6 +8,7 @@ import {
   Button,
   Form,
   Input,
+  InputNumber,
   Row,
   Col,
   Divider,
@@ -30,6 +31,7 @@ import {
 import {
   listSites,
   updateSiteBranding,
+  updateSite,
   getMe,
   type Site,
   type SiteBrandingPayload,
@@ -71,6 +73,8 @@ export default function SiteSettings() {
     icp: '',
     contact: '',
   })
+  const [receiveRatioDelta, setReceiveRatioDelta] = useState(0)
+  const [savingRatio, setSavingRatio] = useState(false)
 
   const loadSite = useCallback(async (id: number) => {
     setLoading(true)
@@ -100,6 +104,7 @@ export default function SiteSettings() {
         } catch {
           setFooterInfo({})
         }
+        setReceiveRatioDelta(Math.max(0, found.receive_ratio_delta || 0))
       }
     } catch {
       message.error('加载站点设置失败')
@@ -181,6 +186,22 @@ export default function SiteSettings() {
     setAnnouncements(announcements.filter((_, i) => i !== index))
   }
 
+  async function handleSaveReceiveRatio() {
+    if (!siteID) return
+    setSavingRatio(true)
+    try {
+      const updated = await updateSite(siteID, { receive_ratio_delta: receiveRatioDelta })
+      setCurrentSite(updated)
+      setReceiveRatioDelta(Math.max(0, updated.receive_ratio_delta || 0))
+      message.success('收号比例已保存，本站上传账号将按新比例计价')
+    } catch (error: unknown) {
+      const respMessage = (error as { response?: { data?: { message?: string } } })?.response?.data?.message
+      message.error(respMessage || '保存收号比例失败')
+    } finally {
+      setSavingRatio(false)
+    }
+  }
+
   async function handleSave() {
     if (!siteID) return
     setSaving(true)
@@ -249,6 +270,35 @@ export default function SiteSettings() {
         </Space>
       </div>
 
+      <Card loading={loading}>
+        <Space direction="vertical" style={{ width: '100%' }} size="middle">
+          <div>
+            <Typography.Title level={5} style={{ marginBottom: 4 }}>
+              本站收号比例
+            </Typography.Title>
+            <Typography.Text type="secondary">
+              主站回收比例是上限。下调点数越大，号主底价越高、本站利润空间越大，但不能高于主站比例。0 表示与主站一致。
+            </Typography.Text>
+          </div>
+          <Space wrap align="center">
+            <Typography.Text>相对主站下调</Typography.Text>
+            <InputNumber
+              min={0}
+              max={20}
+              step={0.1}
+              precision={1}
+              value={receiveRatioDelta}
+              onChange={(value) => setReceiveRatioDelta(Math.max(0, Number(value || 0)))}
+              addonAfter="点"
+              style={{ width: 160 }}
+            />
+            <Button type="primary" icon={<SaveOutlined />} loading={savingRatio} onClick={() => void handleSaveReceiveRatio()}>
+              保存收号比例
+            </Button>
+          </Space>
+        </Space>
+      </Card>
+
       <Row gutter={24}>
         {/* Left Visual Form Customizer */}
         <Col xs={24} lg={14}>