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

tests/test_chat_join_e2e.c

@@ -258,7 +258,7 @@ static void channel_put_shared(struct UTUN_INSTANCE* inst, int has_priv) {
     topo_node_sqlite_channel_put(inst->topo_sqlite_db, g_sh.ch_id, CH_NAME, g_sh.owner,
         g_sh.ch_x_pub, has_priv ? g_sh.ch_x_priv : NULL,
         g_sh.ch_ed_pub, has_priv ? g_sh.ch_ed_priv : NULL, g_sh.ch_sig);
-    chat_core_ensure_channel_ready(g_sh.ch_id);
+    chat_core_ensure_channel_ready(inst, g_sh.ch_id);
 }
 
 static void member_put_self(struct UTUN_INSTANCE* inst, const char* name) {
@@ -317,7 +317,7 @@ static int child_main(const char* role, const char* dir, int invalid_key) {
         /* invite_build требует conn_presence узла — может отставать от paths; ретраим */
         { int built = 0;
           for (int a = 0; a < 1000; a++) {
-              if (chat_invite_build_link(ch_num, target, NULL, link, sizeof(link)) == 0) { built = 1; break; }
+              if (chat_invite_build_link(inst, ch_num, target, NULL, link, sizeof(link)) == 0) { built = 1; break; }
               uasync_poll(inst->ua, POLL_MS);
           }
           if (!built) { fprintf(stderr, "A: invite_build_link failed (target=0x%016llx)\n", (unsigned long long)target); goto out; }
@@ -390,7 +390,7 @@ static int child_main(const char* role, const char* dir, int invalid_key) {
         if (addrs_len <= 0) { fprintf(stderr, "J: serialize addrs failed\n"); goto out; }
 
         uint64_t key = invalid_key ? (d.join_key ^ 0xDEADBEEFCAFEBABEULL) : d.join_key;
-        chat_sync_connect_from_invite(d.channelId, d.nodeId, d.pubkey,
+        chat_sync_connect_from_invite(inst, d.channelId, d.nodeId, d.pubkey,
             addrs_buf, d.addrCount, addrs_len, d.password_len ? d.password : NULL, key);
 
         if (invalid_key) {