feat(marketing): implement recharge tiers and coupon management across admin, server, and uniapp

pwuniapp/common/api.js

@@ -579,6 +579,37 @@ export async function getNavCategories() {
   return null;
 }
 
+/**
+ * 获取钱包充值阶梯与赠送配置列表 (真实从 MySQL 读取)
+ */
+export async function getRechargeTiers() {
+  try {
+    const res = await http.get('/marketing/recharge-tiers');
+    if (Array.isArray(res) && res.length > 0) {
+      return res;
+    }
+  } catch (err) {
+    console.warn('[API] 获取充值阶梯异常:', err.message);
+  }
+  return null;
+}
+
+/**
+ * 获取可用优惠券列表 (支持品类过滤)
+ */
+export async function getMarketingCoupons(category) {
+  try {
+    const query = category ? `?category=${category}` : '';
+    const res = await http.get(`/marketing/coupons${query}`);
+    if (Array.isArray(res) && res.length > 0) {
+      return res;
+    }
+  } catch (err) {
+    console.warn('[API] 获取营销优惠券异常:', err.message);
+  }
+  return null;
+}
+