Avalonia12 (#7)

* ava12升级

* Enable centralized package versioning

Add <Project> and <PropertyGroup> with <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally> to Directory.Packages.props to enable centralized package version management across the repository. This allows package versions to be controlled from this single file instead of individual project files.

* Migrate codebase to Avalonia 12 APIs

Apply Avalonia 12 migration changes: replace SystemDecorations with WindowDecorations and remove ExtendClientAreaChromeHints/ExtendClientAreaTitleBarHeightHint usages; update BindingPlugins removal logic (no-op); switch clipboard usage to ClipboardExtensions.SetTextAsync; update Bitmap.CopyPixels calls to the new signature. Replace TextBox.Watermark with PlaceholderText, convert NumberBox styles to FANumberBox and adjust templates, change Checked/Unchecked handlers to IsCheckedChanged, and adapt FluentIcons usages (SymbolIconSource -> FASymbol/FAFont/FluentIcon equivalents). Fix MainWindow partial classes to inherit Window and correct missing variables/fields/usings. Add migration docs/specs/tasks under .trae and include a small TestFluentIcons project for icon testing.

* Migrate to Avalonia 12 and Plugin SDK v5

Upgrade project to the Avalonia 12 baseline and Plugin SDK v5: centralize Avalonia packages, remove legacy WebView.Avalonia usage (use NativeWebView/WebView2 EnvironmentRequested), and update Fluent/Material icon/package usages. Bump multiple package/project versions to 5.0.0 and Avalonia 12.0.1, update plugin template and README/docs to SDK v5, and add PLUGIN_SDK_V5_MIGRATION.md.

Also fix runtime/behavior bugs: make DataLocationResolver use a fixed bootstrap launcher data path and avoid recursive ResolveDataRoot; add legacy-state handling and extraction in OobeStateService; and update component settings tests to reflect migrated storage (DB/backup) and reset cache for test reloads. Various csproj, tests, and docs updated to reflect the migration and ensure build/test compatibility.

* Update icon glyphs and symbol mappings

Replace and refine icon sources across settings pages and controls: many FAFontIconSource glyphs were updated to specific Seagull Fluent Icons codepoints, some FASymbolIconSource usages were replaced with FAFontIconSource, and a number of symbol-to-Symbol enum mappings were adjusted (e.g. "Bell" -> AlertOn, "Shield" -> ShieldLock). Also clarified a comment in SettingsWindow and fixed a trailing newline in StudySettingsPage. Changes standardize icon visuals and bridge FluentIcons glyphs into FluentAvalonia icon sources.

* fix.修复合并产生的问题。

LanMountainDesktop/App.axaml.cs

@@ -14,7 +14,6 @@ using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Styling;
 using Avalonia.Threading;
-using AvaloniaWebView;
 using LanMountainDesktop.ComponentSystem;
 using LanMountainDesktop.DesktopHost;
 using LanMountainDesktop.Models;
@@ -78,7 +77,6 @@ public partial class App : Application
     private TransparentOverlayWindow? _transparentOverlayWindow;
     private FusedDesktopComponentLibraryWindow? _fusedComponentLibraryWindow;
     private bool _mainWindowClosed;
-    private bool _uiUnhandledExceptionHooked;
     private DesktopShellHost? _desktopShellHost;
     private PublicIpcHostService? _publicIpcHostService;
     private LoadingStateManager? _loadingStateManager;
@@ -194,8 +192,6 @@ public partial class App : Application
             return;
         }
 
-        ConfigureWebViewUserDataFolder();
-        AvaloniaWebViewBuilder.Initialize(default);
         ApplyThemeFromSettings();
         ApplyCurrentCultureFromSettings();
         EnsureSettingsWindowService();
@@ -212,8 +208,7 @@ public partial class App : Application
         }
 
         AppLogger.Info("App", "Framework initialization completed.");
-        
-        RegisterUiUnhandledExceptionGuard();
+
         LinuxDesktopEntryInstaller.EnsureInstalled();
         InitializePublicIpc();
         CurrentSingleInstanceService?.StartActivationListener(ActivateMainWindow);
@@ -532,43 +527,8 @@ public partial class App : Application
 
     private void DisableAvaloniaDataAnnotationValidation()
     {
-        // Get an array of plugins to remove
-        var dataValidationPluginsToRemove =
-            BindingPlugins.DataValidators.OfType<DataAnnotationsValidationPlugin>().ToArray();
-
-        // remove each entry found
-        foreach (var plugin in dataValidationPluginsToRemove)
-        {
-            BindingPlugins.DataValidators.Remove(plugin);
-        }
-    }
-
-    private static void ConfigureWebViewUserDataFolder()
-    {
-        if (!OperatingSystem.IsWindows())
-        {
-            return;
-        }
-
-        const string userDataFolderEnvVar = "WEBVIEW2_USER_DATA_FOLDER";
-        try
-        {
-            if (!string.IsNullOrWhiteSpace(Environment.GetEnvironmentVariable(userDataFolderEnvVar)))
-            {
-                return;
-            }
-
-            var userDataFolder = WebView2RuntimeProbe.ResolveUserDataFolder();
-            Environment.SetEnvironmentVariable(
-                userDataFolderEnvVar,
-                userDataFolder,
-                EnvironmentVariableTarget.Process);
-        }
-        catch (Exception ex)
-        {
-            // Keep startup resilient if user profile folders are unavailable.
-            AppLogger.Warn("WebView2", "Failed to configure WebView2 user data folder.", ex);
-        }
+        // Avalonia 12 中 BindingPlugins 已移除，数据验证插件不再需要手动禁用
+        // 编译型绑定默认开启，数据注解验证行为已改变
     }
 
     private void InitializePluginRuntime()
@@ -1178,43 +1138,6 @@ public partial class App : Application
         _appearanceThemeService.ApplyThemeResources(Resources);
     }
 
-    private void RegisterUiUnhandledExceptionGuard()
-    {
-        if (_uiUnhandledExceptionHooked)
-        {
-            return;
-        }
-
-        Dispatcher.UIThread.UnhandledException += OnUiThreadUnhandledException;
-        _uiUnhandledExceptionHooked = true;
-    }
-
-    private void OnUiThreadUnhandledException(object? sender, DispatcherUnhandledExceptionEventArgs e)
-    {
-        if (!IsKnownWebViewStartupException(e.Exception))
-        {
-            return;
-        }
-
-        e.Handled = true;
-        AppLogger.Warn(
-            "WebView2",
-            "Suppressed a known WebView startup exception from AvaloniaWebView.Navigate to keep the host process alive.",
-            e.Exception);
-    }
-
-    private static bool IsKnownWebViewStartupException(Exception exception)
-    {
-        if (exception is not NullReferenceException)
-        {
-            return false;
-        }
-
-        var stackTrace = exception.StackTrace ?? string.Empty;
-        return stackTrace.Contains("AvaloniaWebView.WebView.Navigate", StringComparison.Ordinal) &&
-               stackTrace.Contains("AvaloniaWebView.WebView.OnAttachedToVisualTree", StringComparison.Ordinal);
-    }
-
     private void ReleaseSingleInstanceAfterExit(string source)
     {
         if (_singleInstanceReleased)
@@ -1959,4 +1882,3 @@ public partial class App : Application
     }
 }
 
-