fix: query-terminal stream, enable-mouse/bracketed-paste methods, simple-backend draw-ellipsis position

backend/simple.lisp

@@ -101,5 +101,8 @@ POS is :top-left, :top-right, :bottom-left, :bottom-right,
 
 (defmethod draw-ellipsis ((b simple-backend) x y width
                           &key fg bg)
-  (declare (ignore x y width fg bg))
+  (declare (ignore width fg bg))
+  ;; Position using newlines+spaces (simple-backend pattern)
+  (dotimes (row y) (backend-write b (string #\Newline)))
+  (backend-write b (make-string x :initial-element #\Space))
   (backend-write b "..."))