feat: 完成 opsx-licence 许可证管理平台全栈实现

基于 opsx-web-lite 框架（Go+Gin+Vue3+Element Plus）构建许可证管理服务器，
业务域参考 Licence 服务器 Web 版。

【后端 - 4层架构】
- 认证：单 Admin 表 + JWT（HS256）
- 核心授权域：Product / Customer / License / Activation
  · License 生成/验证/激活/机器绑定/心跳/续期/吊销
  · 客户端契约接口：/api/v1/license/{verify,activate,deactivate,heartbeat}
- 定价订单：Plan / Order / 支付网关配置
- 防重复购买：CustomerEntitlement + 幂等支付 webhook + 手动发放
- 分析审计：Dashboard 统计 / Analytics / AuditLog / Setting 管理

【前端】
- Dashboard（ECharts 图表）、产品、客户、License、计划、订单、权益、日志、设置
- 9 个完整 CRUD 业务页面 + 登录/布局

【部署】
- SQLite + 单二进制（//go:embed 嵌入前端）
- 开发：./run.sh start（前端5181/后端9001）
- 生产：./run.sh build && ./run.sh binary start
- 默认账号：admin/admin

Author: Logan.Li

backend/utils/audit.go

@@ -0,0 +1,62 @@
+package utils
+
+import (
+	"backend/internal/model"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+)
+
+// LogAction 记录操作日志（成功） // Logan.Li
+func LogAction(db *gorm.DB, c *gin.Context, action, targetType string, targetID uint, targetName, oldData, newData, detail string) {
+	logEntry := model.AuditLog{
+		Action:     action,
+		TargetType: targetType,
+		TargetID:   targetID,
+		TargetName: targetName,
+		OldData:    oldData,
+		NewData:    newData,
+		Detail:     detail,
+		Result:     "success",
+		IP:         c.ClientIP(),
+		CreatedAt:  time.Now(),
+	}
+
+	// 从上下文中获取操作人信息（管理后台调用时存在） // Logan.Li
+	if c != nil {
+		if userID, exists := c.Get("user_id"); exists {
+			if id, ok := userID.(uint); ok {
+				logEntry.UserID = id
+			}
+		}
+		if username, exists := c.Get("username"); exists {
+			if name, ok := username.(string); ok {
+				logEntry.Username = name
+			}
+		}
+	}
+
+	db.Create(&logEntry)
+}
+
+// LogSystemAction 记录系统操作日志（无 HTTP 上下文，如支付回调） // Logan.Li
+func LogSystemAction(db *gorm.DB, action, targetType string, targetID uint, targetName, detail, ip string) {
+	db.Create(&model.AuditLog{
+		UserID:     0,
+		Username:   "system",
+		Action:     action,
+		TargetType: targetType,
+		TargetID:   targetID,
+		TargetName: targetName,
+		Detail:     detail,
+		Result:     "success",
+		IP:         ip,
+		CreatedAt:  time.Now(),
+	})
+}
+
+// GetClientIP 获取客户端真实 IP（兼容代理） // Logan.Li
+func GetClientIP(c *gin.Context) string {
+	return c.ClientIP()
+}

backend/utils/jwt.go

@@ -0,0 +1,54 @@
+package utils
+
+import (
+	"errors"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+// Claims JWT 声明 // Logan.Li
+type Claims struct {
+	UserID   uint   `json:"user_id"`
+	Username string `json:"username"`
+	Role     string `json:"role"`
+	jwt.RegisteredClaims
+}
+
+// GenerateToken 生成 JWT 令牌（HS256，24h 过期） // Logan.Li
+func GenerateToken(userID uint, username, role, secret string) (string, error) {
+	claims := Claims{
+		UserID:   userID,
+		Username: username,
+		Role:     role,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(24 * time.Hour)),
+			IssuedAt:  jwt.NewNumericDate(time.Now()),
+			Issuer:    "opsx-licence",
+		},
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString([]byte(secret))
+}
+
+// ParseToken 解析并校验 JWT 令牌 // Logan.Li
+func ParseToken(tokenString, secret string) (*Claims, error) {
+	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
+		// 确保使用 HMAC 签名方法，防止算法混淆攻击 // Logan.Li
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, errors.New("非预期的签名算法")
+		}
+		return []byte(secret), nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
+		return claims, nil
+	}
+
+	return nil, errors.New("无效的令牌")
+}

backend/utils/license.go

@@ -0,0 +1,89 @@
+package utils
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"strings"
+	"time"
+)
+
+// GenerateLicenseKey 生成 License 密钥（格式: LIC-YYYY-XXXX-XXXX-XXXX-XXXX） // Logan.Li
+func GenerateLicenseKey() string {
+	bytes := make([]byte, 16)
+	_, _ = rand.Read(bytes)
+
+	year := time.Now().Year()
+	part1 := hex.EncodeToString(bytes[0:4])
+	part2 := hex.EncodeToString(bytes[4:8])
+	part3 := hex.EncodeToString(bytes[8:12])
+	part4 := hex.EncodeToString(bytes[12:16])
+
+	return fmt.Sprintf("LIC-%d-%s-%s-%s-%s",
+		year,
+		strings.ToUpper(part1[:4]),
+		strings.ToUpper(part2[:4]),
+		strings.ToUpper(part3[:4]),
+		strings.ToUpper(part4[:4]))
+}
+
+// GenerateOrderNo 生成唯一订单号（格式: ORD-YYYYMMDD-XXXXXXXX） // Logan.Li
+func GenerateOrderNo() string {
+	bytes := make([]byte, 4)
+	_, _ = rand.Read(bytes)
+	return fmt.Sprintf("ORD-%s-%s", time.Now().Format("20060102"), strings.ToUpper(hex.EncodeToString(bytes)))
+}
+
+// CalculateDaysLeft 计算剩余天数（向下取整，最小为 0） // Logan.Li
+func CalculateDaysLeft(endDate time.Time) int {
+	diff := endDate.Sub(time.Now())
+	days := int(diff.Hours() / 24)
+	if days < 0 {
+		return 0
+	}
+	return days
+}
+
+// IsLicenseExpired 检查 License 是否过期 // Logan.Li
+func IsLicenseExpired(endDate time.Time) bool {
+	return time.Now().After(endDate)
+}
+
+// IsExpiringSoon 检查 License 是否即将到期 // Logan.Li
+func IsExpiringSoon(endDate time.Time, warningDays int) bool {
+	daysLeft := CalculateDaysLeft(endDate)
+	return daysLeft > 0 && daysLeft <= warningDays
+}
+
+// ParseFeatures 解析产品功能列表 JSON 为字符串切片 // Logan.Li
+func ParseFeatures(featuresJSON string) []string {
+	if featuresJSON == "" {
+		return []string{}
+	}
+	trimmed := strings.Trim(featuresJSON, "[]")
+	if trimmed == "" {
+		return []string{}
+	}
+	// 简单解析：去引号后按逗号分割 // Logan.Li
+	trimmed = strings.ReplaceAll(trimmed, `"`, "")
+	parts := strings.Split(trimmed, ",")
+	result := make([]string, 0, len(parts))
+	for _, p := range parts {
+		if s := strings.TrimSpace(p); s != "" {
+			result = append(result, s)
+		}
+	}
+	return result
+}
+
+// FormatFeatures 将功能列表格式化为 JSON 字符串 // Logan.Li
+func FormatFeatures(features []string) string {
+	if len(features) == 0 {
+		return "[]"
+	}
+	quoted := make([]string, len(features))
+	for i, f := range features {
+		quoted[i] = fmt.Sprintf(`"%s"`, f)
+	}
+	return fmt.Sprintf("[%s]", strings.Join(quoted, ","))
+}

backend/utils/password.go

@@ -0,0 +1,14 @@
+package utils
+
+import "golang.org/x/crypto/bcrypt"
+
+// HashPassword 对明文密码进行 bcrypt 哈希 // Logan.Li
+func HashPassword(password string) string {
+	hashed, _ := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	return string(hashed)
+}
+
+// CheckPassword 校验明文密码与哈希是否匹配 // Logan.Li
+func CheckPassword(password, hash string) bool {
+	return bcrypt.CompareHashAndPassword([]byte(hash), []byte(password)) == nil
+}