feat: 重构前后端架构，添加Go后端和Python Agent服务

- 新增 Go 语言后端服务(server/)，包含用户认证、Agent管理、数据库连接等API
- 新增 Python Agent 服务(agent/)，实现Agent核心逻辑和工具集
- 前端从原生HTML迁移到Vue.js框架(web/src/)
- 添加 Docker Compose 支持(docker-compose.yml)
- 添加项目架构文档(docs/ARCHITECTURE.md)
- 添加环境变量示例(.env.example)和本地启动脚本(start-local.ps1)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/internal/service/auth_service.go

@@ -0,0 +1,145 @@
+package service
+
+import (
+	"errors"
+	"time"
+
+	"x-agents/server/internal/model"
+	"x-agents/server/internal/repository"
+
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/google/uuid"
+	"golang.org/x/crypto/bcrypt"
+)
+
+var (
+	ErrInvalidCredentials = errors.New("invalid credentials")
+	ErrUserNotFound        = errors.New("user not found")
+)
+
+type AuthService struct {
+	jwtSecret string
+	userRepo  *repository.UserRepository
+}
+
+func NewAuthService(jwtSecret string, userRepo *repository.UserRepository) *AuthService {
+	return &AuthService{
+		jwtSecret: jwtSecret,
+		userRepo:  userRepo,
+	}
+}
+
+type LoginRequest struct {
+	Username string `json:"username" binding:"required"`
+	Password string `json:"password" binding:"required"`
+}
+
+type LoginResponse struct {
+	Token string      `json:"token"`
+	User  *model.User `json:"user"`
+}
+
+func (s *AuthService) Login(req LoginRequest) (*LoginResponse, error) {
+	// 查找用户
+	user, err := s.userRepo.FindByUsername(req.Username)
+	if err != nil {
+		return nil, ErrInvalidCredentials
+	}
+
+	// 验证密码
+	if err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(req.Password)); err != nil {
+		return nil, ErrInvalidCredentials
+	}
+
+	// 生成Token
+	token, err := s.generateToken(user)
+	if err != nil {
+		return nil, err
+	}
+
+	return &LoginResponse{
+		Token: token,
+		User:  user,
+	}, nil
+}
+
+func (s *AuthService) generateToken(user *model.User) (string, error) {
+	claims := jwt.MapClaims{
+		"sub":       user.ID,
+		"username":  user.Username,
+		"role":      user.RoleID,
+		"exp":       time.Now().Add(time.Hour * 24 * 7).Unix(), // 7天有效期
+		"iat":       time.Now().Unix(),
+		"expires_at": time.Now().Add(time.Hour * 24 * 7).Format(time.RFC3339),
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+	return token.SignedString([]byte(s.jwtSecret))
+}
+
+func (s *AuthService) ValidateToken(tokenString string) (jwt.MapClaims, error) {
+	token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, errors.New("unexpected signing method")
+		}
+		return []byte(s.jwtSecret), nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	if claims, ok := token.Claims.(jwt.MapClaims); ok && token.Valid {
+		return claims, nil
+	}
+
+	return nil, errors.New("invalid token")
+}
+
+func (s *AuthService) Register(username, password, email string) (*model.User, error) {
+	// 检查用户是否已存在
+	_, err := s.userRepo.FindByUsername(username)
+	if err == nil {
+		return nil, errors.New("user already exists")
+	}
+
+	// 加密密码
+	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	if err != nil {
+		return nil, err
+	}
+
+	// 创建用户
+	user := &model.User{
+		ID:        uuid.New().String(),
+		Username:  username,
+		Password:  string(hashedPassword),
+		Email:     email,
+		RoleID:    "user",
+		IsActive:  true,
+	}
+
+	// 如果没有用户，创建默认管理员角色
+	role, err := s.userRepo.FindRoleByID(user.RoleID)
+	if err != nil {
+		// 创建默认角色
+		role = &model.Role{
+			ID:          "user",
+			Name:        "user",
+			Permissions: []model.PermissionLevel{model.PermissionRead, model.PermissionWrite},
+		}
+		s.userRepo.CreateRole(role)
+		user.Role = role
+	}
+
+	if err := s.userRepo.Create(user); err != nil {
+		return nil, err
+	}
+
+	return user, nil
+}
+
+// GetUserByID 根据ID获取用户
+func (s *AuthService) GetUserByID(id string) (*model.User, error) {
+	return s.userRepo.FindByID(id)
+}