Fedora Silverblue and other image-based GNOME systems ship neither zenity
nor kdialog, so Open Notebook, Insert Picture, Attach File, Save As,
Export as PDF and the other file pickers did nothing there. They now ask
the FileChooser portal, which also takes the button label and starting
folder that zenity ignored, and fall back to zenity or kdialog where no
portal answers. Opening a notebook folder, an attachment, a recording or
a link goes through the OpenURI portal before xdg-open. Printing shares
the portal request code.

Assisted-by: claude-opus-5.5