fix(windows): prevent console window flash

- Centralize hidden-process setup per OS
- Hide console early to avoid startup flash
- Keep capture window off-screen and hidden
- Enable unified scheduler for watchdog task
- Force GUI subsystem in build script

main.go

@@ -42,10 +42,9 @@ func main() {
 	flag.Parse()
 
 	if *foreground {
+		instance.AllowConsoleKill()
 		instance.ShowConsole()
 	} else {
-		instance.ProtectFromConsoleClose()
-		instance.HideConsole()
 		_ = helpers.AttachLogFile()
 	}