feat: update Godot integration and coordinated package dependencies

Tests/ShrinkSettingsTests.cs

@@ -1,5 +1,7 @@
 using System.Collections;
 using System.Collections.Generic;
+using System.IO;
+using System.Threading;
 using Cysharp.Threading.Tasks;
 using NUnit.Framework;
 using UnityEngine;
@@ -199,6 +201,48 @@ namespace ShrinkDataSaver.Tests
             CollectionAssert.AreEqual(backupBytes, repairedPrimary);
         });
 
+        [UnityTest]
+        public IEnumerator LoadAsync_FallsBackToSecondaryBackup_WhenPrimaryAndFirstBackupCorrupted() =>
+            UniTask.ToCoroutine(async () =>
+        {
+            ShrinkSettings.Set("lang", "zh_cn");
+            await ShrinkSettings.SaveAsync();
+
+            var backupBytes = await _storage.ReadAsync("settings.json");
+            await _storage.WriteAsync("settings.json.bak2", backupBytes);
+            await _storage.WriteAsync("settings.json.bak1", System.Text.Encoding.UTF8.GetBytes("{ broken"));
+            await _storage.WriteAsync("settings.json", System.Text.Encoding.UTF8.GetBytes("{ broken"));
+
+            ShrinkSettings.ResetForTesting();
+            ShrinkSettings.Initialize(_storage, "settings.json");
+
+            await ShrinkSettings.LoadAsync();
+
+            Assert.AreEqual("zh_cn", ShrinkSettings.Get<string>("lang"));
+            var repairedPrimary = await _storage.ReadAsync("settings.json");
+            CollectionAssert.AreEqual(backupBytes, repairedPrimary);
+        });
+
+        [UnityTest]
+        public IEnumerator SaveAsync_PropagatesStorageFailure() => UniTask.ToCoroutine(async () =>
+        {
+            ShrinkSettings.ResetForTesting();
+            ShrinkSettings.Initialize(new FailingStorageProvider(), "settings.json");
+            ShrinkSettings.Set("lang", "zh_cn");
+
+            var failed = false;
+            try
+            {
+                await ShrinkSettings.SaveAsync();
+            }
+            catch (IOException)
+            {
+                failed = true;
+            }
+
+            Assert.IsTrue(failed);
+        });
+
         // ── Overwrite ──
 
         [Test]
@@ -208,5 +252,23 @@ namespace ShrinkDataSaver.Tests
             ShrinkSettings.Set("key", "second");
             Assert.AreEqual("second", ShrinkSettings.Get<string>("key"));
         }
+
+        private sealed class FailingStorageProvider : IStorageProvider
+        {
+            public UniTask WriteAsync(string path, byte[] data, CancellationToken ct = default) =>
+                throw new IOException("write failed");
+
+            public UniTask<byte[]> ReadAsync(string path, CancellationToken ct = default) =>
+                throw new FileNotFoundException(path);
+
+            public UniTask<bool> ExistsAsync(string path, CancellationToken ct = default) =>
+                UniTask.FromResult(false);
+
+            public UniTask DeleteAsync(string path, CancellationToken ct = default) =>
+                UniTask.CompletedTask;
+
+            public UniTask<string[]> ListAsync(string prefix = "", CancellationToken ct = default) =>
+                UniTask.FromResult(System.Array.Empty<string>());
+        }
     }
 }