Organizer: free(): invalid pointer (abort) when the session ends #291

main at 963c3d4 (deb from 2026-10-12 afternoon, 9.0.0~beta.2 + today's fixes), Debian 13, GNOME on X11, local data. Closing the Organizer ended the session normally (data server, gateway and broker stopped), then the terminal showed

free(): invalid pointer
Aborted (core dumped)

coredumpctl names /opt/ecce/bin/organizer (SIGABRT, 14:45:11); no core was stored and the journal has no stack trace. The window's close button may have been clicked twice.

Suspects: a second close (wxEVT_CLOSE_WINDOW) arriving while the frame is already being destroyed, so something is deleted twice; or teardown of code new in this build: the grid's Ctrl+click handler (GridEvtHandler, b0617d7, #290) and the Progress box's finished state (8cd2c2a, #284).

To reproduce: on Xvfb, start the Organizer with a project and a finished calculation selected (Progress box shown), then send two close requests in quick succession (the Organizer test hook), and also one close; run under gdb or with ASan to get the stack.