Merge latest 5 commits from ppy/master while preserving fork behavior on conflicts - #349

Internal offset adjust is based on [survey
results](https://docs.google.com/forms/d/1bWdwN9LPB4dJsqh2NO4z0HBiMiod1k8-tJN5oca-1Iw/edit)
results (mean: 17.95, median: 24.5) with slight skewing based on
cherry-picking results and personal experiences.

For users which have had the setting disabled:

<img width="1380" height="774" alt="osu! 2026-05-21 at 09 19 06"
src="https://github.com/user-attachments/assets/0526517a-fa0b-485b-ac1b-b61b2fccd2af"
/>

For users which are already using it:

<img width="1380" height="774" alt="osu! 2026-05-21 at 09 20 24"
src="https://github.com/user-attachments/assets/1bd77b39-5d75-43e8-8fe1-b324064b25fa"
/>

Note the button is intentionally hidden to avoid any confusion (it's
inverse now, so some users may mistakenly click it). Assume if a user is
already on the new engine, they are happy with it.

Test migration dialog in startup game flow using:

```diff
diff --git a/osu.Game/OsuGame.cs b/osu.Game/OsuGame.cs
index 4bd5ab8..091af6d428 100644
--- a/osu.Game/OsuGame.cs
+++ b/osu.Game/OsuGame.cs
@@ -1315,6 +1315,8 @@ protected override void LoadComplete()
         /// </remarks>
         private void applyConfigMigrations()
         {
+            dialogOverlay.Push(new MigrateNewAudioDialog(true));
+
             // arrives as 2020.123.0-lazer
             string rawVersion = LocalConfig.Get<string>(OsuSetting.Version);
 

```

---------

Co-authored-by: Bartłomiej Dach <dach.bartlomiej@gmail.com>

Agent-Logs-Url: https://github.com/winnerspiros/osu/sessions/2d91ee13-1e66-4df6-8db3-cf2a32a6b15e

Co-authored-by: winnerspiros <1675249+winnerspiros@users.noreply.github.com>

Agent-Logs-Url: https://github.com/winnerspiros/osu/sessions/e6082aeb-9082-4038-8ea9-4bd898edac78

Co-authored-by: winnerspiros <1675249+winnerspiros@users.noreply.github.com>

Agent-Logs-Url: https://github.com/winnerspiros/osu/sessions/ab2ee4ea-fd9a-4375-ae5f-14317e61a903

Co-authored-by: winnerspiros <1675249+winnerspiros@users.noreply.github.com>