feat: migrate auth module to modular domain pattern

internal/domain/auth.go

@@ -0,0 +1,23 @@
+package domain
+
+import (
+	"context"
+	"mal/internal/db"
+)
+
+type User = db.User
+type Session = db.Session
+
+type AuthService interface {
+	Login(ctx context.Context, username, password string) (*Session, error)
+	ValidateSession(ctx context.Context, sessionID string) (*User, error)
+	Logout(ctx context.Context, sessionID string) error
+}
+
+type AuthRepository interface {
+	GetUserByUsername(ctx context.Context, username string) (*User, error)
+	GetUserByID(ctx context.Context, id string) (*User, error)
+	CreateSession(ctx context.Context, userID string, sessionID string) (*Session, error)
+	GetSession(ctx context.Context, sessionID string) (*Session, error)
+	DeleteSession(ctx context.Context, sessionID string) error
+}