dm: прямой обмен сообщениями (DM) + soundtouch + архитектура звонков

- src/dm/: dm_core/dm_crypto/dm_mailbox — прямой обмен сообщениями (DM)
- lib/soundtouch-master/: vendored SoundTouch (изменение темпа/высоты аудио)
- doc/dm_arch.md, doc/chat_call_arch.md: архитектура DM и звонков
- tests: test_dm.c, test_dm_e2e.c
- chat: рефакторинг chat_* модулей, member_sync, invite_build
- chatgui/chatgui-android: синхронизация с новым API чата
- lib/u_async, debug_config, utun_instance: сопутствующие изменения

tools/chatgui/transport/utun_node.cpp

@@ -90,6 +90,7 @@ void UtunNode::stop() {
 }
 
 void UtunNode::finalize() {
+    gui_bridge_set_inst(nullptr);
     if (m_ua) { uasync_destroy(m_ua, 0); m_ua = nullptr; }
     m_instance = nullptr;
     m_running = false;
@@ -234,6 +235,7 @@ void UtunNode::runLoop() {
 
     /* set ua for gui_bridge before init, so GUI can post */
     gui_bridge_set_uasync(ua);
+    gui_bridge_set_inst(m_instance);
 
     if (utun_instance_init(m_instance) != 0) {
         QMetaObject::invokeMethod(this, [this] { emit error("utun_instance_init failed"); });
@@ -254,14 +256,15 @@ void UtunNode::runLoop() {
     utun_add_nodeinfo_cbk(m_instance, gui_nodeinfo_cb_impl, nullptr);
 
     /* Bridge chat events to GUI via gui_bridge */
-    chat_event_set_handler([](int type, const uint8_t* data, int len) {
+    chat_event_set_handler(m_instance, [](struct UTUN_INSTANCE* inst, int type, const uint8_t* data, int len) {
+        (void)inst;
         gui_bridge_post(type, data, len);
     });
 
     /* Initialize chat_core (DB) and chat_sync (channel/message P2P sync) */
     chat_core_init(m_instance, QString(m_dbPath + "/chats.db").toUtf8().constData());
     chat_sync_init(m_instance);
-    chat_core_sync_my_addresses();
+    chat_core_sync_my_addresses(m_instance);
 
     DEBUG_DEBUG(DEBUG_CATEGORY_GENERAL, "chat_core + chat_sync initialized");
     DEBUG_DEBUG(DEBUG_CATEGORY_GENERAL, "utun_node: entering poll loop");