[tests] Fix CreateAndBuildProjectTemplate hang/flakiness for Mac Catalyst (#26564)

Two issues in the 'Execute'/'DeleteSavedState' helpers used by the Mac Catalyst 'CreateAndBuildProjectTemplate' tests could cause the test process to hang for 30 seconds (or longer) waiting on an unattended 'Do you want to try to reopen its windows again?' AppKit modal dialog:

 * 'DeleteSavedState' only deleted '<bundleid>.savedState', but macOS stores Mac Catalyst apps' saved state under '<bundleid>~iosmac.savedState' (the 'iosmac' personality suffix), so the saved state was never actually being cleaned up.

 * Even with a clean Saved Application State folder, AppKit also tracks a separate persistent 'crash history' per bundle identifier that isn't stored in that folder and isn't cleared by deleting it. After many crashed/killed test runs sharing the same default bundle identifier, this alone could still trigger the modal.

Fix both: delete the '~iosmac' saved-state variant too, and set the application default 'ApplePersistenceIgnoreState' to 'YES', which tells AppKit to skip the restore-prompt flow entirely regardless of any tracked crash history.

Copilot-Session: 0d41380a-e6ee-470e-b837-68411050a4f6

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: rolfbjarne

tests/dotnet/UnitTests/TestBaseClass.cs

@@ -488,8 +488,6 @@ protected Execution Execute (string executable, out string output, out string ma
 			if (!File.Exists (executable))
 				throw new FileNotFoundException ($"The executable '{executable}' does not exists.");
 
-			DeleteSavedState (executable);
-
 			magicWord = Guid.NewGuid ().ToString ();
 			var env = new Dictionary<string, string?> {
 				{ "MAGIC_WORD", magicWord },
@@ -500,54 +498,71 @@ protected Execution Execute (string executable, out string output, out string ma
 					env [kvp.Key] = kvp.Value;
 			}
 
-			var rv = Execution.RunAsync (executable, Array.Empty<string> (), environment: env, timeout: TimeSpan.FromSeconds (30)).Result;
-			output = rv.Output.MergedOutput;
-
-			DeleteSavedState (executable);
-
-			return rv;
+			DeleteSavedState (executable, false);
+			try {
+				var rv = Execution.RunAsync (executable, Array.Empty<string> (), environment: env, timeout: TimeSpan.FromSeconds (30)).Result;
+				output = rv.Output.MergedOutput;
+				return rv;
+			} finally {
+				// Remove the override so it doesn't affect a later test using the same bundle identifier.
+				DeleteSavedState (executable, true);
+			}
 		}
 
 		// Delete the saved application state for the app being launched, to prevent
 		// the "Do you want to try to reopen its windows again?" dialog from showing
 		// if the app crashed during a previous test run. See https://github.com/dotnet/macios/issues/25922
-		static void DeleteSavedState (string executable)
+		static void DeleteSavedState (string executable, bool cleanup)
+		{
+			var bundleIdentifier = GetBundleIdentifier (executable);
+			if (string.IsNullOrEmpty (bundleIdentifier))
+				return;
+
+			var savedStateParentDir = Path.Combine (Environment.GetFolderPath (Environment.SpecialFolder.UserProfile), "Library", "Saved Application State");
+			// Mac Catalyst apps run under the "iosmac" personality, and macOS stores their saved state
+			// with a "~iosmac" suffix added to the bundle identifier, so delete both variants.
+			foreach (var identifier in new [] { bundleIdentifier, $"{bundleIdentifier}~iosmac" }) {
+				var savedStateDir = Path.Combine (savedStateParentDir, $"{identifier}.savedState");
+				try {
+					if (Directory.Exists (savedStateDir)) {
+						Directory.Delete (savedStateDir, true);
+						Console.WriteLine ($"Deleted saved application state: {savedStateDir}");
+					}
+
+					if (cleanup) {
+						Execution.RunAsync ("/usr/bin/defaults", new [] { "delete", bundleIdentifier, "ApplePersistenceIgnoreState" }, timeout: TimeSpan.FromSeconds (30)).Wait ();
+					} else {
+						Execution.RunAsync ("/usr/bin/defaults", new [] { "write", bundleIdentifier, "ApplePersistenceIgnoreState", "-bool", "YES" }, timeout: TimeSpan.FromSeconds (30)).Wait ();
+					}
+				} catch (Exception e) {
+					Console.WriteLine ($"Could not delete saved application state '{savedStateDir}': {e.Message}");
+				}
+			}
+		}
+
+		static string? GetBundleIdentifier (string executable)
 		{
 			// Find the .app bundle directory from the executable path
 			var dir = Path.GetDirectoryName (executable);
 			while (!string.IsNullOrEmpty (dir) && !dir.EndsWith (".app", StringComparison.OrdinalIgnoreCase))
 				dir = Path.GetDirectoryName (dir);
 
 			if (string.IsNullOrEmpty (dir))
-				return;
+				return null;
 
 			// Read the bundle identifier from Info.plist
-			string? bundleIdentifier = null;
 			var infoPlistPath = Path.Combine (dir, "Contents", "Info.plist");
 			if (!File.Exists (infoPlistPath))
 				infoPlistPath = Path.Combine (dir, "Info.plist");
 			if (!File.Exists (infoPlistPath))
-				return;
+				return null;
 
 			try {
 				var infoPlist = PDictionary.OpenFile (infoPlistPath);
-				bundleIdentifier = infoPlist.GetString ("CFBundleIdentifier")?.Value;
+				return infoPlist.GetString ("CFBundleIdentifier")?.Value;
 			} catch (Exception e) {
 				Console.WriteLine ($"Could not read bundle identifier from '{infoPlistPath}': {e.Message}");
-				return;
-			}
-
-			if (string.IsNullOrEmpty (bundleIdentifier))
-				return;
-
-			var savedStateDir = Path.Combine (Environment.GetFolderPath (Environment.SpecialFolder.UserProfile), "Library", "Saved Application State", $"{bundleIdentifier}.savedState");
-			try {
-				if (Directory.Exists (savedStateDir)) {
-					Directory.Delete (savedStateDir, true);
-					Console.WriteLine ($"Deleted saved application state: {savedStateDir}");
-				}
-			} catch (Exception e) {
-				Console.WriteLine ($"Could not delete saved application state '{savedStateDir}': {e.Message}");
+				return null;
 			}
 		}