Fix Quick Accent Y umlaut availability across language selection modes

Agent-Logs-Url: https://github.com/microsoft/PowerToys/sessions/c1eaede2-276c-4e81-ab45-64a502bd211e

Co-authored-by: niels9001 <9866362+niels9001@users.noreply.github.com>

src/modules/poweraccent/PowerAccent.Core/Languages.cs

@@ -744,6 +744,7 @@ namespace PowerAccent.Core
                 LetterKey.VK_I => new[] { "í" },
                 LetterKey.VK_O => new[] { "ó", "ő", "ö" },
                 LetterKey.VK_U => new[] { "ú", "ű", "ü" },
+                LetterKey.VK_Y => new[] { "ÿ", "ý" },
                 LetterKey.VK_COMMA => new[] { "„", "”", "»", "«" },
                 _ => Array.Empty<string>(),
             };

src/modules/poweraccent/PowerAccent.Core/Services/SettingsService.cs

@@ -61,11 +61,31 @@ public class SettingsService
                         ExcludedApps = settings.Properties.ExcludedApps.Value;
                         _keyboardListener.UpdateExcludedApps(ExcludedApps);
 
-                        SelectedLang = settings.Properties.SelectedLang.Value
+                        var rawLanguageStrings = settings.Properties.SelectedLang.Value
                             .Split(',', StringSplitOptions.RemoveEmptyEntries)
-                            .Select(lang => Enum.TryParse(lang, out Language selectedLangValue) ? selectedLangValue : Language.SPECIAL)
+                            .Select(lang => lang.Trim())
                             .ToArray();
 
+                        if (rawLanguageStrings.Any(lang => string.Equals(lang, "ALL", StringComparison.OrdinalIgnoreCase)))
+                        {
+                            SelectedLang = Enum.GetValues<Language>();
+                        }
+                        else
+                        {
+                            SelectedLang = rawLanguageStrings
+                                .Select(lang =>
+                                {
+                                    if (Enum.TryParse(lang, true, out Language selectedLangValue))
+                                    {
+                                        return selectedLangValue;
+                                    }
+
+                                    Logger.LogWarning($"Unknown QuickAccent language setting '{lang}', falling back to SPECIAL.");
+                                    return Language.SPECIAL;
+                                })
+                                .ToArray();
+                        }
+
                         switch (settings.Properties.ToolbarPosition.Value)
                         {
                             case "Top center":