feat: 对齐 Waffo 包年/永久结账与客户端席位 API

同步 OpsXShell 档位定价与 Waffo 商品映射，补齐 checkout/webhook/设备列表契约，便于桌面端购买与满席释放。

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

backend/internal/service/payment/waffo.go

@@ -0,0 +1,153 @@
+package payment
+
+import (
+	"fmt"
+	"net/url"
+	"os"
+	"strings"
+)
+
+// WaffoConfig hosted checkout settings for pancake.waffo.ai // Logan.Li
+type WaffoConfig struct {
+	CheckoutURL        string
+	StoreSlug          string
+	ProductID          string
+	ProductIDYearly    string
+	ProductIDPerpetual string
+	Currency           string
+	Environment        string
+	SuccessURL         string
+}
+
+// LoadWaffoConfig reads WAFFO_* env vars (same names as OpsXShell legacy license-server). // Logan.Li
+func LoadWaffoConfig() WaffoConfig {
+	env := strings.TrimSpace(os.Getenv("WAFFO_ENVIRONMENT"))
+	if env == "" {
+		env = "test"
+	}
+	success := strings.TrimSpace(os.Getenv("SUCCESS_URL"))
+	if success == "" {
+		success = "opsxshell://pro/activated"
+	}
+	currency := strings.TrimSpace(os.Getenv("WAFFO_CURRENCY"))
+	if currency == "" {
+		currency = "CNY"
+	}
+	defaultProduct := strings.TrimSpace(os.Getenv("WAFFO_PRODUCT_ID"))
+	yearly := strings.TrimSpace(os.Getenv("WAFFO_PRODUCT_ID_YEARLY"))
+	perpetual := strings.TrimSpace(os.Getenv("WAFFO_PRODUCT_ID_PERPETUAL"))
+	if yearly == "" {
+		yearly = defaultProduct
+	}
+	if perpetual == "" {
+		perpetual = defaultProduct
+	}
+	return WaffoConfig{
+		CheckoutURL:        strings.TrimSpace(os.Getenv("WAFFO_CHECKOUT_URL")),
+		StoreSlug:          strings.TrimSpace(os.Getenv("WAFFO_STORE_SLUG")),
+		ProductID:          defaultProduct,
+		ProductIDYearly:    yearly,
+		ProductIDPerpetual: perpetual,
+		Currency:           currency,
+		Environment:        env,
+		SuccessURL:         success,
+	}
+}
+
+// BuildCheckoutURL returns a Waffo hosted checkout URL with order/device/email metadata. // Logan.Li
+func BuildCheckoutURL(cfg WaffoConfig, orderNo, deviceID, email, returnURL, planType string) (string, error) {
+	success := cfg.SuccessURL
+	if strings.TrimSpace(returnURL) != "" {
+		success = strings.TrimSpace(returnURL)
+	}
+	u, err := resolveBaseCheckoutURL(cfg, planType)
+	if err != nil {
+		return "", err
+	}
+	q := u.Query()
+	if q.Get("successUrl") == "" {
+		q.Set("successUrl", appendQuery(success, map[string]string{
+			"orderNo":  orderNo,
+			"deviceId": deviceID,
+			"email":    email,
+			"planType": planType,
+		}))
+	}
+	if deviceID != "" {
+		q.Set("deviceId", deviceID)
+	}
+	if orderNo != "" {
+		q.Set("orderNo", orderNo)
+	}
+	if email != "" {
+		q.Set("email", email)
+	}
+	if planType != "" {
+		q.Set("planType", planType)
+	}
+	u.RawQuery = q.Encode()
+	return u.String(), nil
+}
+
+func productIDForPlan(cfg WaffoConfig, planType string) string {
+	switch strings.TrimSpace(planType) {
+	case "yearly", "monthly":
+		return cfg.ProductIDYearly
+	case "perpetual", "lifetime":
+		return cfg.ProductIDPerpetual
+	default:
+		if cfg.ProductIDPerpetual != "" {
+			return cfg.ProductIDPerpetual
+		}
+		return cfg.ProductID
+	}
+}
+
+func checkoutTypeForPlan(planType string) string {
+	switch strings.TrimSpace(planType) {
+	case "yearly", "monthly":
+		return "subscription"
+	default:
+		return "onetime"
+	}
+}
+
+func resolveBaseCheckoutURL(cfg WaffoConfig, planType string) (*url.URL, error) {
+	// Single WAFFO_CHECKOUT_URL only as absolute fallback when no store/products configured.
+	// Prefer store + per-plan product IDs so yearly/perpetual map to different Waffo SKUs.
+	productID := productIDForPlan(cfg, planType)
+	if cfg.StoreSlug != "" && productID != "" {
+		raw := fmt.Sprintf("https://pancake.waffo.ai/store/%s/product/%s", cfg.StoreSlug, productID)
+		u, err := url.Parse(raw)
+		if err != nil {
+			return nil, err
+		}
+		q := u.Query()
+		q.Set("type", checkoutTypeForPlan(planType))
+		q.Set("currency", cfg.Currency)
+		if cfg.Environment == "test" {
+			q.Set("test", "true")
+		}
+		u.RawQuery = q.Encode()
+		return u, nil
+	}
+	if cfg.CheckoutURL != "" {
+		return url.Parse(cfg.CheckoutURL)
+	}
+	return nil, fmt.Errorf("未配置 WAFFO_STORE_SLUG 与 WAFFO_PRODUCT_ID_YEARLY / WAFFO_PRODUCT_ID_PERPETUAL（或 WAFFO_CHECKOUT_URL）")
+}
+
+func appendQuery(raw string, values map[string]string) string {
+	u, err := url.Parse(raw)
+	if err != nil {
+		return raw
+	}
+	q := u.Query()
+	for k, v := range values {
+		if v != "" {
+			q.Set(k, v)
+		}
+	}
+	u.RawQuery = q.Encode()
+	return u.String()
+}