Fix exception when setting Folder Search action keyword in Explorer plugin

- Fix (false, false) case in EditActionKeyword to break gracefully instead
  of throwing ArgumentException. This handles the valid scenario where the
  user changes a disabled keyword's text but keeps it disabled.
- Fix GetActiveActionKeywords to return an empty dictionary instead of null
  when actionKeywordStr is null/empty, preventing NullReferenceException.
- Fix ActionKeyword setter to only auto-enable when the value actually
  changes, preventing unintended side-effects during construction.
- Initialize ActionKeywordSetting backing fields directly in constructor to
  avoid the auto-enable triggering during initialization.
- Change TextBox binding to UpdateSourceTrigger=PropertyChanged so the
  checkbox auto-enables as the user types (before they click the checkbox),
  fixing the checkbox toggle issue caused by LostFocus timing.

Co-authored-by: Jack251970 <53996452+Jack251970@users.noreply.github.com>

Author: Copilot

Plugins/Flow.Launcher.Plugin.Explorer/Settings.cs

@@ -230,7 +230,7 @@ internal enum ActionKeyword
         internal Dictionary<ActionKeyword, string> GetActiveActionKeywords(string actionKeywordStr)
         {
             var result = new Dictionary<ActionKeyword, string>();
-            if (string.IsNullOrEmpty(actionKeywordStr)) return null;
+            if (string.IsNullOrEmpty(actionKeywordStr)) return result;
             foreach (var action in Enum.GetValues<ActionKeyword>())
             {
                 var keywordStr = GetActionKeyword(action);

Plugins/Flow.Launcher.Plugin.Explorer/ViewModels/SettingsViewModel.cs

@@ -321,8 +321,9 @@ private void EditActionKeyword(object obj)
                     Context.API.AddActionKeyword(Context.CurrentPluginMetadata.ID, actionKeywordWindow.ActionKeyword);
                     break;
                 case (false, false):
-                    throw new ArgumentException(
-                        $"Both false in {nameof(actionKeyword)}.{nameof(actionKeyword.Enabled)} and {nameof(actionKeywordWindow)}.{nameof(actionKeywordWindow.KeywordEnabled)} should suggest that the ShowDialog() result is false");
+                    // Keyword was disabled and remains disabled, but the keyword text was changed.
+                    // No action keyword registration changes needed; the model will be updated below.
+                    break;
             }
 
             (actionKeyword.Keyword, actionKeyword.Enabled) = (actionKeywordWindow.ActionKeyword, actionKeywordWindow.KeywordEnabled);

Plugins/Flow.Launcher.Plugin.Explorer/Views/ActionKeywordSetting.xaml

@@ -82,7 +82,7 @@
                         VerticalAlignment="Center"
                         DataObject.Pasting="TextBox_Pasting"
                         PreviewKeyDown="TxtCurrentActionKeyword_OnKeyDown"
-                        Text="{Binding ActionKeyword}" />
+                        Text="{Binding ActionKeyword, UpdateSourceTrigger=PropertyChanged}" />
                 </StackPanel>
                 <StackPanel Margin="0 10 0 15" Orientation="Horizontal">
                     <TextBlock

Plugins/Flow.Launcher.Plugin.Explorer/Views/ActionKeywordSetting.xaml.cs

@@ -16,9 +16,9 @@ public string ActionKeyword
             get => actionKeyword;
             set
             {
-                // Set Enable to be true if user change ActionKeyword
-                KeywordEnabled = true;
-                _ = SetProperty(ref actionKeyword, value);
+                // Set Enable to be true only when the ActionKeyword value actually changes
+                if (SetProperty(ref actionKeyword, value))
+                    KeywordEnabled = true;
             }
         }
 
@@ -34,8 +34,9 @@ public bool KeywordEnabled
         public ActionKeywordSetting(ActionKeywordModel selectedActionKeyword)
         {
             CurrentActionKeyword = selectedActionKeyword;
-            ActionKeyword = selectedActionKeyword.Keyword;
-            KeywordEnabled = selectedActionKeyword.Enabled;
+            // Initialize backing fields directly to avoid triggering the auto-enable side-effect
+            actionKeyword = selectedActionKeyword.Keyword;
+            _keywordEnabled = selectedActionKeyword.Enabled;
 
             InitializeComponent();