Wiresheet: arrow nudges keep the selection and the sheet's focus

Ctrl+A hands the sheet the keyboard, and repainting the same sheet keeps
whatever of the selection is still on it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

main.py

@@ -1357,6 +1357,8 @@ def select_all_boxes(event=None):
             return None
     wiresheet.deselect_link()        # links and boxes are never selected together
     select_canvas_boxes(list(app_state.canvas_comp_map))
+    # Hand the sheet the keyboard, so the arrows move the boxes rather than the tree.
+    app_state.canvas.focus_set()
     count = len(app_state.selected_canvas_tags)
     app_state.set_status(f"{count} component{'s' if count != 1 else ''} selected.")
     return "break"
@@ -2270,7 +2272,15 @@ def nudge_selected_boxes(dx, dy):
                       "meta_before": meta_prop.get("val") if meta_prop is not None else None})
         canvas.move(tag, shift_x, shift_y)
     app_state.drag_data.update(tag=tags[0], group=group, moved=True, collapse_to=None)
+    pressed_last = app_state.selected_canvas_tag
     on_canvas_release(None)
+    # The same boxes stay selected, and the sheet keeps the keyboard, so the next
+    # arrow press moves them again.
+    still_here = [t for t in tags if t in app_state.canvas_comp_map and t != pressed_last]
+    if pressed_last in app_state.canvas_comp_map:
+        still_here.append(pressed_last)
+    select_canvas_boxes(still_here)
+    canvas.focus_set()
     return "break"