fix(gui): widen Keep Pairs input (80->140) and switch to drag_int

- src/gui_2.py:3829 set_next_item_width 80 -> 140, input_int -> drag_int
- Tests adapted to mock drag_int alongside input_int (5 test files)

tests/test_discussion_truncate_layout.py

@@ -0,0 +1,18 @@
+import inspect
+from src import gui_2
+
+def test_keep_pairs_input_uses_adequate_width():
+ src = inspect.getsource(gui_2)
+ marker = "Keep Pairs:"
+ idx = src.find(marker)
+ assert idx != -1, "Could not find Keep Pairs label in gui_2.py"
+ snippet = src[idx:idx + 200]
+ assert "set_next_item_width(80)" not in snippet, (
+  "Keep Pairs input width is still 80px; digit values get clipped."
+ )
+ assert "set_next_item_width(140)" in snippet, (
+  "Keep Pairs input should use width 140 for 2-3 digit values."
+ )
+ assert "drag_int" in snippet, (
+  "Keep Pairs input should use drag_int for inline +/- controls."
+ )