feat: 通用授权后台、离线证、Waffo 支付页与仪表盘加强

支持多产品计划展示、LICOFF 离线签发、支付独立配置与调试，以及分析看板；同步更新 README 与集成文档。

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

backend/internal/service/license/offline_service.go

@@ -0,0 +1,177 @@
+package license
+
+import (
+	"backend/config"
+	"backend/internal/dto"
+	"backend/internal/model"
+	"backend/utils"
+	"errors"
+	"strings"
+	"time"
+
+	"gorm.io/gorm"
+)
+
+// OfflineIssuer 离线许可证签发（绑定 device_id，最长 365 天） // Logan.Li
+type OfflineIssuer struct {
+	db *gorm.DB
+	kp *utils.OfflineKeyPair
+}
+
+// NewOfflineIssuer 创建离线签发器；seed 为空时返回可用实例但 Issue 会失败 // Logan.Li
+func NewOfflineIssuer(db *gorm.DB, cfg *config.Config) *OfflineIssuer {
+	issuer := &OfflineIssuer{db: db}
+	if cfg == nil || strings.TrimSpace(cfg.OfflineLicenseSeed) == "" {
+		return issuer
+	}
+	kp, err := utils.DeriveOfflineKeyPair(cfg.OfflineLicenseSeed)
+	if err == nil {
+		issuer.kp = kp
+	}
+	return issuer
+}
+
+// PublicKeyHex 返回当前公钥 hex（桌面嵌入对照） // Logan.Li
+func (s *OfflineIssuer) PublicKeyHex() string {
+	if s == nil || s.kp == nil {
+		return ""
+	}
+	return s.kp.OfflinePublicKeyHex()
+}
+
+// Issue 签发离线序列号并落库审计记录 // Logan.Li
+func (s *OfflineIssuer) Issue(req dto.OfflineLicenseCreate) (*dto.OfflineLicenseResponse, error) {
+	if s == nil || s.kp == nil {
+		return nil, errors.New("未配置 OFFLINE_LICENSE_SEED，无法签发离线证")
+	}
+
+	deviceID := strings.TrimSpace(req.DeviceID)
+	if deviceID == "" {
+		return nil, errors.New("device_id 不能为空")
+	}
+
+	planType := strings.TrimSpace(req.PlanType)
+	if planType == "" {
+		planType = "yearly"
+	}
+	if planType != "trial" && planType != "yearly" {
+		return nil, errors.New("离线证仅允许体验(trial)或包年(yearly)，禁止永久")
+	}
+
+	duration := req.DurationDays
+	if duration <= 0 {
+		duration = utils.OfflineMaxDurationDays
+	}
+	if duration > utils.OfflineMaxDurationDays {
+		return nil, errors.New("离线证有效期不得超过 365 天")
+	}
+	if planType == "trial" && duration > 180 {
+		duration = 180
+	}
+
+	productCode := strings.TrimSpace(req.ProductCode)
+	if productCode == "" {
+		productCode = "opsxshell"
+	}
+
+	var product model.Product
+	if err := s.db.Where("code = ?", productCode).First(&product).Error; err != nil {
+		return nil, errors.New("产品不存在: " + productCode)
+	}
+
+	var customer model.Customer
+	if req.CustomerID > 0 {
+		if err := s.db.First(&customer, req.CustomerID).Error; err != nil {
+			return nil, errors.New("客户不存在")
+		}
+	} else {
+		email := strings.TrimSpace(req.Email)
+		name := strings.TrimSpace(req.CustomerName)
+		if name == "" {
+			name = "离线客户"
+		}
+		if email != "" {
+			err := s.db.Where("email = ?", email).First(&customer).Error
+			if err != nil {
+				customer = model.Customer{Name: name, Email: email, Status: 1}
+				if err := s.db.Create(&customer).Error; err != nil {
+					return nil, errors.New("创建客户失败")
+				}
+			}
+		} else {
+			customer = model.Customer{Name: name, Email: "", Status: 1}
+			if err := s.db.Create(&customer).Error; err != nil {
+				return nil, errors.New("创建客户失败")
+			}
+		}
+	}
+
+	now := time.Now().UTC()
+	exp := now.AddDate(0, 0, duration)
+	claims := utils.OfflineLicenseClaims{
+		V:            1,
+		ProductCode:  product.Code,
+		DeviceID:     deviceID,
+		Email:        strings.TrimSpace(req.Email),
+		PlanType:     planType,
+		IssuedAt:     now.Unix(),
+		ExpiresAt:    exp.Unix(),
+		MaxDevices:   1,
+		CustomerName: customer.Name,
+	}
+
+	serial, err := utils.SignOfflineLicense(s.kp, claims)
+	if err != nil {
+		return nil, err
+	}
+
+	notes := strings.TrimSpace(req.Notes)
+	if notes == "" {
+		notes = "离线许可证"
+	}
+	notes = notes + " | device=" + deviceID + " | plan=" + planType
+
+	lic := model.License{
+		LicenseKey:         serial,
+		CustomerID:         customer.ID,
+		ProductID:          product.ID,
+		Status:             model.LicenseStatusActive,
+		StartDate:          now,
+		EndDate:            exp,
+		Duration:           duration,
+		MaxActivations:     1,
+		CurrentActivations: 1,
+		IsTrial:            planType == "trial",
+		TrialDays:          duration,
+		Notes:              notes,
+	}
+	if err := s.db.Create(&lic).Error; err != nil {
+		return nil, errors.New("保存离线 License 失败")
+	}
+
+	activation := model.Activation{
+		LicenseID:   lic.ID,
+		DeviceID:    deviceID,
+		DeviceName:  "offline",
+		Status:      "active",
+		IsOnline:    false,
+		ActivatedAt: now,
+		ExpiresAt:   &exp,
+		LastSeenAt:  now,
+	}
+	_ = s.db.Create(&activation).Error
+
+	return &dto.OfflineLicenseResponse{
+		Serial:      serial,
+		DeviceID:    deviceID,
+		Email:       claims.Email,
+		PlanType:    planType,
+		ProductCode: product.Code,
+		IssuedAt:    now.Format(time.RFC3339),
+		ExpiresAt:   exp.Format(time.RFC3339),
+		Duration:    duration,
+		MaxDevices:  1,
+		LicenseID:   lic.ID,
+		PublicKey:   s.kp.OfflinePublicKeyHex(),
+	}, nil
+}