feat(openthread): reorganize source file structure

components/openthread/src/esp_openthread_instance.cpp

@@ -0,0 +1,47 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "sdkconfig.h"
+#include "core/instance/instance.hpp"
+#include "esp_openthread.h"
+#include "esp_openthread_instance.h"
+#include "esp_openthread_ncp.h"
+#include "openthread/instance.h"
+#include "openthread/tasklet.h"
+
+bool esp_openthread_instances_init(void)
+{
+    return otInstanceInitSingle() != NULL;
+}
+
+void esp_openthread_instances_deinit(otInstance *instance)
+{
+    otInstanceFinalize(instance);
+}
+
+bool esp_openthread_tasklets_are_pending(otInstance *instance)
+{
+    return otTaskletsArePending(instance);
+}
+
+void esp_openthread_tasklets_process(otInstance *instance)
+{
+    while (otTaskletsArePending(instance)) {
+        otTaskletsProcess(instance);
+    }
+}
+
+#if CONFIG_OPENTHREAD_RADIO
+void esp_openthread_ncp_app_init(otInstance *instance)
+{
+    otAppNcpInit(instance);
+}
+#endif
+
+otInstance *esp_openthread_get_instance(void)
+{
+    return (otInstance *)&ot::Instance::Get();
+}