Exercises the runtime paths that had never run (details in
docs/rewrite/notes/verification-VR.md):
- IME: replay steps drive the surface's real GtkIMContext handlers with
a real preedit + attributes; preedit renders under the cursor and
commits reach the pty, incl. dead-key and compose orderings.
- Paste and OSC 52 read/write confirmation dialogs: allow, deny and
remember flows.
- Quick terminal on niri via wlr-layer-shell: positions, sizes, toggle
and autohide. Fixes a real bug: link order could put libwayland-client
ahead of libgtk4-layer-shell, silently disabling the quick terminal;
apprt-gtk now loads libwayland-client via wayland-sys dlopen.
- Flatpak host commands against a zbus mock of
org.freedesktop.Flatpak.Development under dbus-run-session: spawn,
exit status, cwd/env/fd forwarding and SIGHUP on stop, both directly
and through termio Exec (flatpak-info path seam added).
- Horizontal-scroll tab switching thresholds and reset.
tests/gtk_replay.rs runs the real binary against the session display
(skips without one).
Test Plan:
- cargo test --test gtk_replay (needs a Wayland/X11 display)
- cargo test -p ghostty-os --test flatpak_mock; -p ghostty-termio
--test flatpak_exec