internal/system: relocate from system

These packages are highly specific to hakurei and are difficult to use safely from other pieces of code.

Their exported symbols are made available until v0.4.0 where they will be removed for #24.

Signed-off-by: Ophestra <cat@gensokyo.uk>

system/wayland/deprecated.go

@@ -0,0 +1,27 @@
+// Package wayland exposes the internal/system/wayland package.
+//
+// Deprecated: This package will be removed in 0.4.
+package wayland
+
+import (
+	_ "unsafe" // for go:linkname
+
+	"hakurei.app/internal/system/wayland"
+)
+
+// Conn represents a connection to the wayland display server.
+type Conn = wayland.Conn
+
+const (
+	// WaylandDisplay contains the name of the server socket
+	// (https://gitlab.freedesktop.org/wayland/wayland/-/blob/1.23.1/src/wayland-client.c#L1147)
+	// which is concatenated with XDG_RUNTIME_DIR
+	// (https://gitlab.freedesktop.org/wayland/wayland/-/blob/1.23.1/src/wayland-client.c#L1171)
+	// or used as-is if absolute
+	// (https://gitlab.freedesktop.org/wayland/wayland/-/blob/1.23.1/src/wayland-client.c#L1176).
+	WaylandDisplay = wayland.Display
+
+	// FallbackName is used as the wayland socket name if WAYLAND_DISPLAY is unset
+	// (https://gitlab.freedesktop.org/wayland/wayland/-/blob/1.23.1/src/wayland-client.c#L1149).
+	FallbackName = wayland.FallbackName
+)