feat(register-and-statistics): add user registration endpoint

- Added `POST /auth/register` endpoint to support user registration.
- Implemented registration logic in `auth.go` with dynamic role assignment.
- Integrated settings `AllowRegister` and `DefaultRole` for registration flow.
- Updated imports to include new modules: `conf`, `setting`.
- Adjusted user creation logic to use `DefaultRole` setting dynamically.

server/handles/auth.go

@@ -9,8 +9,10 @@ import (
 	"time"
 
 	"github.com/Xhofe/go-cache"
+	"github.com/alist-org/alist/v3/internal/conf"
 	"github.com/alist-org/alist/v3/internal/model"
 	"github.com/alist-org/alist/v3/internal/op"
+	"github.com/alist-org/alist/v3/internal/setting"
 	"github.com/alist-org/alist/v3/server/common"
 	"github.com/gin-gonic/gin"
 	"github.com/pquerna/otp/totp"
@@ -89,6 +91,40 @@ func loginHash(c *gin.Context, req *LoginReq) {
 	loginCache.Del(ip)
 }
 
+type RegisterReq struct {
+	Username string `json:"username" binding:"required"`
+	Password string `json:"password" binding:"required"`
+}
+
+// Register a new user
+func Register(c *gin.Context) {
+	if !setting.GetBool(conf.AllowRegister) {
+		common.ErrorStrResp(c, "registration is disabled", 403)
+		return
+	}
+	var req RegisterReq
+	if err := c.ShouldBind(&req); err != nil {
+		common.ErrorResp(c, err, 400)
+		return
+	}
+	user := &model.User{
+		Username: req.Username,
+		Role:     model.Roles{setting.GetInt(conf.DefaultRole, int(model.GUEST))},
+		Authn:    "[]",
+	}
+	user.SetPassword(req.Password)
+	if err := op.CreateUser(user); err != nil {
+		common.ErrorResp(c, err, 500, true)
+		return
+	}
+	token, err := common.GenerateToken(user)
+	if err != nil {
+		common.ErrorResp(c, err, 500, true)
+		return
+	}
+	common.SuccessResp(c, gin.H{"token": token})
+}
+
 type UserResp struct {
 	model.User
 	Otp         bool                    `json:"otp"`

server/router.go

@@ -61,6 +61,7 @@ func Init(e *gin.Engine) {
 	api.POST("/auth/login", handles.Login)
 	api.POST("/auth/login/hash", handles.LoginHash)
 	api.POST("/auth/login/ldap", handles.LoginLdap)
+	api.POST("/auth/register", handles.Register)
 	auth.GET("/me", handles.CurrentUser)
 	auth.POST("/me/update", handles.UpdateCurrent)
 	auth.GET("/me/sshkey/list", handles.ListMyPublicKey)