v0.8.0: move position-cursor out of dirty-guarded redraw and out of dialog-guarded let — runs every frame unconditional

Removed (position-cursor fb w h) from inside redraw (which is gated by dirty
flags), and from inside the dialog-guarded (unless dialog* ...) block in the
main loop. Added unconditional (position-cursor be w h) at loop body level so
it runs every single iteration regardless of dirty state or dialog activity.
This ensures the cursor highlight always tracks cursor-pos correctly.

org/channel-tui-view.org

@@ -339,7 +339,6 @@ and current sidebar mode (:auto/:visible/:hidden)."
     (when (sidebar-visible-p w)
       (view-sidebar fb w h))
     (cl-tty.backend:end-sync fb)
-    (position-cursor fb w h)
     (setf (st :dirty) (list nil nil nil))))
 
 (defun position-cursor (fb w h)