feat(tray): 实现 tray_cleanup 并在 backend_destroy 中调用以释放托盘资源

src/backend/x11/backend.c

@@ -195,6 +195,8 @@ backend_t *backend_create(const char *display_name) {
 void backend_destroy(backend_t *backend) {
   if (!backend) return;
 
+  tray_cleanup(backend);
+
   p_delete(&backend->config_list.cfgs);
   p_clear(&backend->config_list, 1);
 

src/backend/x11/tray.c

@@ -243,3 +243,12 @@ void tray_init(
   tray_broadcast_manager(tray, backend);
   xcb_flush(backend->conn);
 }
+
+void tray_cleanup(backend_t *backend) {
+  auto conn = backend->conn;
+  auto tray = backend->tray;
+
+  xcb_destroy_window(conn, tray->container);
+  p_clear(backend->tray, 1);
+  p_delete(&backend->tray);
+}

src/backend/x11/tray.h

@@ -15,3 +15,4 @@ void tray_init(
   int32_t host_width,
   int32_t host_height
 );
+void tray_cleanup(backend_t *backend);