feat: ToNav-go v1.0.0 - 内部服务导航系统

功能:
- 前台导航: 分类Tab切换、实时搜索、健康状态指示、响应式适配
- 后台管理: 服务/分类CRUD、系统设置、登录认证(bcrypt)
- 健康检查: 定时检测(5min)、独立检查URL、三态指示(在线/离线/未检测)
- 云端备份: WebDAV上传/下载/恢复/删除、定时自动备份、本地备份管理

技术栈: Go + Gin + GORM + SQLite

handlers/auth.go

@@ -0,0 +1,121 @@
+package handlers
+
+import (
+	"log"
+	"net/http"
+	"tonav-go/database"
+	"tonav-go/models"
+
+	"github.com/gin-contrib/sessions"
+	"github.com/gin-gonic/gin"
+	"golang.org/x/crypto/bcrypt"
+)
+
+// LoginHandler 处理登录请求
+func LoginHandler(c *gin.Context) {
+	var input struct {
+		Username string `form:"username" binding:"required"`
+		Password string `form:"password" binding:"required"`
+	}
+
+	if err := c.ShouldBind(&input); err != nil {
+		c.HTML(http.StatusOK, "login.html", gin.H{"error": "用户名和密码不能为空"})
+		return
+	}
+
+	var user models.User
+	if err := database.DB.Where("username = ?", input.Username).First(&user).Error; err != nil {
+		c.HTML(http.StatusOK, "login.html", gin.H{"error": "用户名或密码错误"})
+		return
+	}
+
+	if err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(input.Password)); err != nil {
+		c.HTML(http.StatusOK, "login.html", gin.H{"error": "用户名或密码错误"})
+		return
+	}
+
+	session := sessions.Default(c)
+	session.Set("user_id", int(user.ID))
+	session.Set("username", user.Username)
+	session.Set("must_change", user.MustChangePassword)
+	if err := session.Save(); err != nil {
+		log.Printf("Session save error: %v", err)
+		c.HTML(http.StatusOK, "login.html", gin.H{"error": "登录失败，请重试"})
+		return
+	}
+
+	if user.MustChangePassword {
+		c.Redirect(http.StatusFound, "/admin/change-password")
+		return
+	}
+	c.Redirect(http.StatusFound, "/admin/dashboard")
+}
+
+// LogoutHandler 处理退出登录
+func LogoutHandler(c *gin.Context) {
+	session := sessions.Default(c)
+	session.Clear()
+	session.Save()
+	c.Redirect(http.StatusFound, "/admin/login")
+}
+
+// ChangePasswordHandler 修改密码
+func ChangePasswordHandler(c *gin.Context) {
+	if c.Request.Method == "GET" {
+		c.HTML(http.StatusOK, "change_password.html", nil)
+		return
+	}
+
+	var input struct {
+		OldPassword     string `form:"old_password" binding:"required"`
+		NewPassword     string `form:"new_password" binding:"required"`
+		ConfirmPassword string `form:"confirm_password" binding:"required"`
+	}
+
+	if err := c.ShouldBind(&input); err != nil {
+		c.HTML(http.StatusOK, "change_password.html", gin.H{"error": "所有字段均为必填"})
+		return
+	}
+
+	if input.NewPassword != input.ConfirmPassword {
+		c.HTML(http.StatusOK, "change_password.html", gin.H{"error": "两次输入的新密码不一致"})
+		return
+	}
+
+	if len(input.NewPassword) < 6 {
+		c.HTML(http.StatusOK, "change_password.html", gin.H{"error": "新密码长度不能少于6位"})
+		return
+	}
+
+	session := sessions.Default(c)
+	userID, err := getSessionUserID(session)
+	if err != nil {
+		c.Redirect(http.StatusFound, "/admin/login")
+		return
+	}
+
+	var user models.User
+	if err := database.DB.First(&user, userID).Error; err != nil {
+		c.HTML(http.StatusOK, "change_password.html", gin.H{"error": "用户不存在"})
+		return
+	}
+
+	if err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(input.OldPassword)); err != nil {
+		c.HTML(http.StatusOK, "change_password.html", gin.H{"error": "旧密码错误"})
+		return
+	}
+
+	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(input.NewPassword), bcrypt.DefaultCost)
+	if err != nil {
+		c.HTML(http.StatusOK, "change_password.html", gin.H{"error": "密码加密失败"})
+		return
+	}
+	user.Password = string(hashedPassword)
+	user.MustChangePassword = false
+	database.DB.Save(&user)
+
+	session.Set("must_change", false)
+	session.Save()
+
+	c.Redirect(http.StatusFound, "/admin/dashboard")
+}