Skip focus restoration when closing an inactive tab

`on_pre_close` restored the group's previous selection for every closing
sheet, so closing a background tab pulled the focus to the previously
active tab. Restore only when the closing sheet is the active sheet of
its group.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: FichteFoll

plugin/listener.py

@@ -140,6 +140,11 @@ def on_pre_close(self, view: sublime.View) -> None:
         if window is None:
             return
 
+        # Closing an inactive tab does not change the focus,
+        # so there is nothing to restore.
+        if window.active_sheet_in_group(group) != sheet:
+            return
+
         state = get_state(window)
         if state.session_active:
             return