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/src/memberlistmodel.cpp

@@ -66,8 +66,11 @@ void MemberListModel::setChannel(const QString& channelId, bool isOwner) {
     endResetModel();
 
     if (!channelId.isEmpty()) {
-        char* ch = u_strdup(channelId.toUtf8().constData());
-        gui_bridge_post_uasync_fn(chat_core_request_member_list_trampoline, ch);
+        struct chat_member_list_req* req = (struct chat_member_list_req*)u_calloc(1, sizeof(*req));
+        if (!req) return;
+        req->inst = gui_bridge_get_inst();
+        strncpy(req->ch_id, channelId.toUtf8().constData(), sizeof(req->ch_id) - 1);
+        gui_bridge_post_uasync_fn(chat_core_request_member_list_trampoline, req);
     }
 }
 
@@ -77,8 +80,11 @@ void MemberListModel::refresh() {
 
 void MemberListModel::refreshRtt() {
     if (m_channelId.isEmpty()) return;
-    char* ch = u_strdup(m_channelId.toUtf8().constData());
-    gui_bridge_post_uasync_fn(chat_core_request_member_rtt_trampoline, ch);
+    struct chat_member_list_req* req = (struct chat_member_list_req*)u_calloc(1, sizeof(*req));
+    if (!req) return;
+    req->inst = gui_bridge_get_inst();
+    strncpy(req->ch_id, m_channelId.toUtf8().constData(), sizeof(req->ch_id) - 1);
+    gui_bridge_post_uasync_fn(chat_core_request_member_rtt_trampoline, req);
 }
 
 quint64 MemberListModel::nodeIdAt(int row) const {