更新支付和推荐系统逻辑，新增根据推荐配置计算支付金额的功能，确保用户享受优惠。调整绑定推荐关系的有效期读取方式，支持从配置中获取。优化提现流程，增加最低提现金额的配置读取，提升系统灵活性和用户体验。同时，更新管理界面中的支付设置链接，确保一致性。

app/api/miniprogram/pay/route.ts

@@ -10,7 +10,7 @@
 
 import { NextResponse } from 'next/server'
 import crypto from 'crypto'
-import { query } from '@/lib/db'
+import { query, getConfig } from '@/lib/db'
 
 // 微信支付配置 - 2026-01-25 更新
 // 小程序支付绑定状态: 审核中（申请单ID: 201554696918）
@@ -101,8 +101,33 @@ export async function POST(request: Request) {
       }, { status: 400 })
     }
 
+    // === 根据推广配置计算好友优惠后的实际支付金额 ===
+    let finalAmount = amount
+    try {
+      // 读取推广/分销配置，获取好友优惠比例（如 5 表示 5%）
+      const referralConfig = await getConfig('referral_config')
+      const userDiscount = referralConfig?.userDiscount ? Number(referralConfig.userDiscount) : 0
+
+      // 若存在有效的推荐码且配置了优惠比例，则给好友打折
+      if (userDiscount > 0 && body.referralCode) {
+        const discountRate = userDiscount / 100
+        const discounted = amount * (1 - discountRate)
+        // 保证至少 0.01 元，并保留两位小数
+        finalAmount = Math.max(0.01, Math.round(discounted * 100) / 100)
+        console.log('[MiniPay] 应用好友优惠:', {
+          originalAmount: amount,
+          discountPercent: userDiscount,
+          finalAmount,
+          referralCode: body.referralCode,
+        })
+      }
+    } catch (e) {
+      console.warn('[MiniPay] 读取 referral_config.userDiscount 失败，使用原价金额:', e)
+      finalAmount = amount
+    }
+
     const orderSn = generateOrderSn()
-    const totalFee = Math.round(amount * 100) // 转换为分
+    const totalFee = Math.round(finalAmount * 100) // 转换为分（单位分）
     const goodsBody = description || (productType === 'fullbook' ? '《一场Soul的创业实验》全书' : `章节购买-${productId}`)
 
     // 获取客户端IP
@@ -207,7 +232,7 @@ export async function POST(request: Request) {
           ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, NOW(), NOW())
         `, [
           orderSn, orderSn, userId, openId,
-          productType, productId || 'fullbook', amount, goodsBody,
+          productType, productId || 'fullbook', finalAmount, goodsBody,
           'created', null, referrerId, orderReferralCode
         ])
       } catch (insertErr: any) {
@@ -224,7 +249,7 @@ export async function POST(request: Request) {
               ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, NOW(), NOW())
             `, [
               orderSn, orderSn, userId, openId,
-              productType, productId || 'fullbook', amount, goodsBody,
+              productType, productId || 'fullbook', finalAmount, goodsBody,
               'created', null, referrerId
             ])
             console.log('[MiniPay] 订单已插入(未含 referral_code，请执行 scripts/add_orders_referral_code.py)')
@@ -238,7 +263,7 @@ export async function POST(request: Request) {
                 ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, NOW(), NOW())
               `, [
                 orderSn, orderSn, userId, openId,
-                productType, productId || 'fullbook', amount, goodsBody,
+                productType, productId || 'fullbook', finalAmount, goodsBody,
                 'created', null
               ])
               console.log('[MiniPay] 订单已插入(未含 referrer_id/referral_code，请执行迁移脚本)')
@@ -257,7 +282,8 @@ export async function POST(request: Request) {
         userId, 
         productType, 
         productId,
-        amount 
+        originalAmount: amount,
+        finalAmount,
       })
     } catch (dbError) {
       console.error('[MiniPay] ❌ 插入订单失败:', dbError)