Fix Dropdown issue

docs/daemon-plan.md

@@ -361,6 +361,12 @@ Start-up orders:
   comes from a build without the action — and `on_activate` re-presents the
   window that is already there instead of building a second one. A stale window
   therefore never stays next to a fresh one, and the daemon is not involved.
+  Closing the old window would drop row edits that were never saved, so the
+  takeover asks it for its rows first (`GetRows` at `/dev/rager/gkeymapper/Window`,
+  see `shared/ipc_ids.h`) and the new `build_ui()` starts from that mappings text
+  instead of from `mappings.conf`. An instance that does not answer — an older
+  build — leaves the new window with the file, and the file stays untouched until
+  the user presses `Save mappings`.
 - Menu, help and options: `Help` (also `F1`) opens a one-page explanation of the
   rows, types, capture dialog, daemon status and tray; `Options` opens a small
   non-modal window with the GUI's own switches (tray behaviour, language,