fix: native file picker 崩溃问题，找不到库时静默崩溃的问题

AGENTS.md

@@ -26,6 +26,8 @@ dotnet run --project src/GUI                            # Launch the Avalonia de
 
 ## Known Issues / Gotchas
 
+- **升级 Avalonia 版本时，必须同步更新所有次级包引用。** 仅修改主包 `Avalonia` 的 Version 不会自动更新 `Avalonia.Desktop`、`Avalonia.Themes.Fluent`、`Avalonia.Fonts.Inter` 等次级包。必须手动逐个修改，然后执行 `dotnet clean && dotnet restore`。否则运行时的原生库（如 `libAvaloniaNative.dylib`）会混用新旧版本，导致 macOS 上的 `StorageProvider` 文件/文件夹选择对话框在回调时 SIGSEGV 崩溃。
+  - 相关 Avalonia issues: [#21102](https://github.com/AvaloniaUI/Avalonia/issues/21102), [#21150](https://github.com/AvaloniaUI/Avalonia/issues/21150), [#21313](https://github.com/AvaloniaUI/Avalonia/issues/21313)，修复 PR: [#21104](https://github.com/AvaloniaUI/Avalonia/pull/21104)。
 - **Tests create temp files/directories** under `Path.GetTempPath()` and clean them up via `IDisposable`. Don't rely on a real audio directory for tests.
 - **`AudioMetadataReader` tests** use real WAV files from `data/source/` (not in git). When files are absent, tests silently return early (`if (wavFiles.Length == 0) return;`) — they pass without actually running assertions, not `Skip.If`. Running `dotnet test` will report 12 passes regardless of whether the fixture files exist.
 - **`.atl.txt` fixture files** are generated by `AtlFieldExtractor`. If the WAV files or the ATL library version change, re-run the extractor to regenerate them before running metadata tests.