diff --git a/.gitignore b/.gitignore
index e43b0f9..ed86553 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 .DS_Store
+build/
diff --git a/AIStudyApp/AIStudyAppTests/MarkedReadStoreTests.swift b/AIStudyApp/AIStudyAppTests/MarkedReadStoreTests.swift
index ab23bfc..ba2c67f 100644
--- a/AIStudyApp/AIStudyAppTests/MarkedReadStoreTests.swift
+++ b/AIStudyApp/AIStudyAppTests/MarkedReadStoreTests.swift
@@ -81,19 +81,7 @@ final class MarkedReadStoreTests: XCTestCase {
         XCTAssertEqual(arr.count, 0)
     }
 
-    // MARK: - Persistence across instances
-
-    func test_state_survives_reinit() {
-        store.mark("mat-survive")
-
-        // Simulate app restart by creating a new instance (singleton in real app,
-        // but we can verify the persisted data is loadable)
-        let newStore = MarkedReadStore.shared
-        // Singleton — same instance. But the key test is: data survived UserDefaults write.
-        XCTAssertTrue(newStore.contains("mat-survive"))
-    }
-
-    // MARK: - Empty string edge cases
+    // MARK: - Edge cases
 
     func test_empty_string_as_id() {
         store.mark("")