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/display.hpp

@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+#pragma once
+
+#include <wayland-server-core.h>
+
+#include "wlr/wlr.hpp"
+
+namespace wlr {
+
+class Display {
+public:
+	Display() : m_display(wl_display_create()) {}
+	~Display() { if (m_display) wl_display_destroy(m_display); }
+
+	Display(const Display&) = delete;
+	Display& operator=(const Display&) = delete;
+	Display(Display&&) = delete;
+	Display& operator=(Display&&) = delete;
+
+	struct wl_display* raw() const { return m_display; }
+	explicit operator bool() const { return m_display != nullptr; }
+	struct wl_event_loop* event_loop() const { return wl_display_get_event_loop(m_display); }
+
+	void set_terminate() { wl_display_terminate(m_display); }
+	void run() { wl_display_run(m_display); }
+	bool init_shm() { return wl_display_init_shm(m_display); }
+	const char* add_socket_auto() {
+		const char* name = wl_display_add_socket_auto(m_display);
+		return name;
+	}
+	void flush_clients() { wl_display_flush_clients(m_display); }
+
+private:
+	struct wl_display* m_display;
+};
+
+}