Gio.DesktopAppInfo.new() returns NULL for a desktop file that doesn't
exist, and PyGObject raises TypeError ("constructor returned NULL")
rather than returning None, so launch()'s `if info is None` never ran.
The exception escaped the control socket's GLib callback, GLib dropped
the watch, and ft-floatd stopped answering everything: the float key,
dock, Launch as Standalone, and profiles, until the desktop restarted.
Found on the Frame (2026-10-02): a profile saved with RustDesk's
Flatpak open records its window's app id, com.carriez.flutter_hbb,
which has no desktop file (the Flatpak's is com.rustdesk.RustDesk).
`ft-layout use` on that profile asked ft-floatd to launch it, and
ft-floatd went silent. With this, that launch replies "error no app
com.carriez.flutter_hbb" and the profile's other apps open.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
