Open with no row selected passed nil to -_setFilename:, and NSOpenPanel boxed it in an
array literal, so the action threw before the modal session was stopped and the panel
stayed up. Both buttons now go through one helper that stops the session only when
this panel is the modal window and always orders the panel out; Open accepts the
selection (filtered by canChooseFiles/canChooseDirectories and multiple-selection),
or the shown directory for directory choosers. Escape cancels.
Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
