feat: 기능 추가 과정중

src/application/result.ts

@@ -0,0 +1,10 @@
+import type { AppFailure } from "../contracts/errors.ts";
+
+/**
+ * The single success/failure carrier used across application input boundaries.
+ * Adapters map technology-specific errors to an application failure before
+ * constructing this value.
+ */
+export type Result<Value, Failure = AppFailure> =
+  | Readonly<{ ok: true; value: Value }>
+  | Readonly<{ ok: false; error: Failure }>;