core: 添加 X11 后端初始化与屏幕信息探测

src/core/backend.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <stddef.h>
+
+#include "wm_desc.h"
+
+typedef struct wm_backend_t wm_backend_t;
+
+typedef struct wm_backend_detect_t {
+  wm_output_info_t *outputs;
+  size_t output_count;
+} wm_backend_detect_t;
+
+wm_backend_t *wm_backend_create(const char *display_name);
+void wm_backend_destroy(wm_backend_t *backend);
+
+wm_backend_detect_t *wm_backend_detect(wm_backend_t *backend);
+void wm_backend_detect_destroy(wm_backend_detect_t *detect);