Fix: Set Normal process priority for logon startup task

The default priority for Windows Task Scheduler tasks is Low (7),
which causes Flow Launcher to be sluggish when other processes are
consuming CPU. Explicitly set the task priority to Normal when
creating the logon startup task.

Also update CheckLogonTask() to recreate the task if the priority
is not Normal, so existing users with the incorrect priority get
automatically fixed on next startup.

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

Author: Copilot

Flow.Launcher/Helper/AutoStartup.cs

@@ -64,7 +64,9 @@ private static bool CheckLogonTask()
                 if (task.Definition.Actions.FirstOrDefault() is Microsoft.Win32.TaskScheduler.Action taskAction)
                 {
                     var action = taskAction.ToString().Trim();
-                    if (!action.Equals(Constant.ExecutablePath, StringComparison.OrdinalIgnoreCase))
+                    var needsRecreation = !action.Equals(Constant.ExecutablePath, StringComparison.OrdinalIgnoreCase)
+                        || task.Definition.Settings.Priority != System.Diagnostics.ProcessPriorityClass.Normal;
+                    if (needsRecreation)
                     {
                         UnscheduleLogonTask();
                         ScheduleLogonTask();
@@ -184,6 +186,7 @@ private static bool ScheduleLogonTask()
         td.Settings.StopIfGoingOnBatteries = false;
         td.Settings.DisallowStartIfOnBatteries = false;
         td.Settings.ExecutionTimeLimit = TimeSpan.Zero;
+        td.Settings.Priority = System.Diagnostics.ProcessPriorityClass.Normal;
 
         try
         {