refactor(data): move Result utility to utils and simplify API

Relocate the Result type from `@/data/result` to `@/utils/result` and
replace the discriminated-union API (`kind`/`value`) with a simpler
boolean-based API (`success`/`data`) across all repositories and
storage classes for improved readability and consistency.

src/data/storage/app/app_storage.ts

@@ -17,7 +17,7 @@
  */
 
 import { LocalStorage } from "../local_storage";
-import { Result, type Result as ResultT } from "../result";
+import { Result, type Result as ResultT } from "@/utils/result";
 import { StorageKeys } from "../storage_keys";
 
 export class AppStorage {
@@ -78,7 +78,7 @@ export class AppStorage {
     todayString: string,
   ): Promise<ResultT<boolean>> {
     const r = await AppStorage.ls.getString(key);
-    if (r.kind === "failure") return r;
-    return Result.success(r.value === null || r.value !== todayString);
+    if (!r.success) return r;
+    return Result.ok(r.data === null || r.data !== todayString);
   }
 }