feat(level):租户等级参与费用计算

internal/logic/billing/level.go

@@ -25,6 +25,31 @@ func GetTenantLevelConfig(ctx context.Context, level int) (*entity.TntTenantLeve
 	return &config, nil
 }
 
+// GetLevelPriceMultiplier 获取租户级别的价格乘数
+// 查询失败时静默返回 1.0，不阻断计费
+func GetLevelPriceMultiplier(ctx context.Context, tenantID int64) float64 {
+	var tenant entity.TntTenants
+	if err := dao.TntTenants.Ctx(ctx).Where("id", tenantID).Scan(&tenant); err != nil || tenant.Id == 0 {
+		g.Log().Warningf(ctx, "[Billing] failed to read tenant level for multiplier: tenantID=%d, err=%v", tenantID, err)
+		return 1.0
+	}
+
+	if tenant.Level <= 1 {
+		return 1.0
+	}
+
+	var config entity.TntTenantLevelConfigs
+	if err := dao.TntTenantLevelConfigs.Ctx(ctx).Where("level", tenant.Level).Scan(&config); err != nil || config.Id == 0 {
+		g.Log().Warningf(ctx, "[Billing] failed to read level config for multiplier: level=%d, err=%v", tenant.Level, err)
+		return 1.0
+	}
+
+	if config.PriceMultiplier > 0 && config.PriceMultiplier != 1.0 {
+		return config.PriceMultiplier
+	}
+	return 1.0
+}
+
 // CheckAndUpgradeLevel 检查并升级租户等级（充值后调用）
 // 升级策略：仅升不降 — max_members/max_concurrency 仅在新值 > 当前值时才更新
 func CheckAndUpgradeLevel(ctx context.Context, tenantID int64) error {
@@ -97,6 +122,9 @@ func CheckAndUpgradeLevel(ctx context.Context, tenantID int64) error {
 	// 7. 清除并发限制缓存
 	_, _ = g.Redis().Do(ctx, "DEL", fmt.Sprintf("tenant:conc_limit:%d", tenantID))
 
+	// 8. 清除该租户的价格缓存（级别变化可能影响折扣）
+	modelPriceCache.DeleteByPattern(ctx, fmt.Sprintf("%d:*", tenantID))
+
 	return nil
 }
 

internal/logic/billing/pricing.go

@@ -212,6 +212,15 @@ func GetModelPrice(ctx context.Context, tenantID int64, modelName string) (*Pric
 		}
 	}
 
+	// 3.5 级别折扣 fallback：当租户×模型维度未设置倍率时，使用租户级别的 price_multiplier
+	if tenantMultiplier == 1.0 {
+		levelMultiplier := GetLevelPriceMultiplier(ctx, tenantID)
+		if levelMultiplier > 0 && levelMultiplier < 1.0 {
+			tenantMultiplier = levelMultiplier
+			discountRatio = levelMultiplier
+		}
+	}
+
 	// 4. 套餐价（待实现）
 	// 前置条件：需新增 pln_plan_model_pricing 表存储每个套餐的每个模型定价，
 	// 或为 pln_plans 增加 billing_discount_ratio 全局折扣字段。

web/admin/src/views/tenant/TenantLevelsPage.vue

@@ -100,14 +100,12 @@ async function handleSubmit() {
   try {
     if (editingId.value) {
       await request.put(`/admin/tenant-level-configs/${editingId.value}`, {
-        update: {
-          name: formData.name,
-          cumulative_recharge_threshold: formData.cumulative_recharge_threshold,
-          max_members: formData.max_members,
-          max_concurrency: formData.max_concurrency,
-          price_multiplier: formData.price_multiplier,
-          sort_order: formData.sort_order,
-        },
+        name: formData.name,
+        cumulative_recharge_threshold: formData.cumulative_recharge_threshold,
+        max_members: formData.max_members,
+        max_concurrency: formData.max_concurrency,
+        price_multiplier: formData.price_multiplier,
+        sort_order: formData.sort_order,
       })
       Message.success('更新成功')
     } else {