[DeedleFake]

Adds plain bindings for wlroots' presentation-time support:

• CreatePresentation wraps wlr_presentation_create;
• Presentation.OnDestroy wraps its destroy event;
• PresentationSurfaceTexturedOnOutput and PresentationSurfaceScannedOutOnOutput wrap wlr_presentation_surface_textured_on_output and wlr_presentation_surface_scanned_out_on_output.

Nothing else changes.

This is stacked on #10, so its base is that branch and the diff only shows this commit. kawa (DeedleFake/kawa#16) is pinned to this branch, which has both.

kawa needs this because GTK 4 crashes without it. A client that has no wp_presentation global falls back to timing frames from the wl_output mode's refresh rate. Nested outputs report that rate as 0, which the protocol allows. Current GTK (4.24 and main, since GNOME/gtk@beb2eda3) divides by it without a check, in gdk_wayland_surface_frame_callback, and dies with SIGFPE. With the global present, GTK uses presentation feedback, and it treats a feedback refresh of 0 as "keep the predicted interval".

Verified with go build ./... and go vet ./... against wlroots 0.20.2. Also verified with kawa built against this branch in a nested X11 session: flatpak run org.gtk.Demo4 now stays up and gets wp_presentation_feedback.presented events. Without the global it exits with status 136 after its first frame.