feat: user / admin / auth 및 전역적으로 사용할 인증 관련 타입 추가

src/main/kotlin/roomescape/common/dto/CommonAuth.kt

@@ -0,0 +1,29 @@
+package roomescape.common.dto
+
+import roomescape.admin.infrastructure.persistence.AdminPermissionLevel
+
+abstract class LoginCredentials {
+    abstract val id: Long
+    abstract val password: String
+}
+
+data class AdminLoginCredentials(
+    override val id: Long,
+    override val password: String,
+    val permissionLevel: AdminPermissionLevel
+) : LoginCredentials()
+
+data class UserLoginCredentials(
+    override val id: Long,
+    override val password: String,
+) : LoginCredentials()
+
+data class CurrentUserContext(
+    val id: Long,
+    val name: String,
+    val type: PrincipalType
+);
+
+enum class PrincipalType {
+    USER, ADMIN
+}