Add C++20 RAII wrapper around wlroots 0.20 + scenefx

Wraps wlroots' C ABI behind owning types (Display, Backend, Compositor,
Output, XdgShell/Toplevel, Seat/Cursor/Keyboard, Scene/Node/Tree) with
wl_signal -> std::function callbacks. Links the scenefx effect engine and
ships a wlr::fx animation helper. Includes a runnable tinywl-style compositor
and a scene/blur demo.

License: AGPL-3.0-only.

include/wlr/wlr.hpp

@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+#pragma once
+
+#include <cmath>
+#include <cstdlib>
+#include <functional>
+#include <iterator>
+#include <limits>
+#include <string>
+#include <utility>
+
+#define static
+extern "C" {
+#include <scenefx/types/wlr_scene.h>
+#include <wlr/types/wlr_compositor.h>
+#include <wlr/types/wlr_output.h>
+#include <wlr/types/wlr_output_layout.h>
+#include <wlr/types/wlr_seat.h>
+#include <wlr/types/wlr_keyboard.h>
+#include <wlr/types/wlr_pointer.h>
+#include <wlr/types/wlr_cursor.h>
+#include <wlr/types/wlr_xdg_shell.h>
+#include <wlr/types/wlr_data_device.h>
+#include <wlr/backend.h>
+#include <wlr/render/wlr_renderer.h>
+#include <wlr/render/allocator.h>
+#include <wlr/version.h>
+}
+#undef static