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-android/headless/headless_control.c

@@ -4,6 +4,7 @@
 #include "headless_control.h"
 #include "../libutun_lite/utun_config_api.h"
 #include "../libutun_lite/invite_link_c.h"
+#include "../libutun_lite/instance_lite.h"
 #include "../../../src/chat/chat_setting.h"
 #include "../../../src/chat/chat_sync.h"
 #include "../../../lib/debug_config.h"
@@ -315,7 +316,13 @@ static int handle_join(int fd, int id, const char* json) {
     }
 
     DEBUG_INFO(DEBUG_CATEGORY_GENERAL, "join: calling chat_sync_connect_from_invite...");
-    chat_sync_connect_from_invite(d.channelId, d.nodeId, d.pubkey, addrs_buf, d.addrCount, addrs_len, d.password, d.join_key);
+    struct UTUN_INSTANCE* inst = instance_lite_get_instance();
+    if (!inst) {
+        DEBUG_ERROR(DEBUG_CATEGORY_GENERAL, "join: no instance running — drop");
+        send_response(fd, id, NULL, "instance not running");
+        return 0;
+    }
+    chat_sync_connect_from_invite(inst, d.channelId, d.nodeId, d.pubkey, addrs_buf, d.addrCount, addrs_len, d.password, d.join_key);
 
     char resp[512];
     snprintf(resp, sizeof(resp),
@@ -331,7 +338,9 @@ static int handle_chat_setting(int fd, int id, const char* json) {
         send_response(fd, id, NULL, "missing name or value");
         return 0;
     }
-    int rc = chat_setting_set(name, value);
+    struct UTUN_INSTANCE* inst = instance_lite_get_instance();
+    if (!inst) { send_response(fd, id, NULL, "instance not running"); return 0; }
+    int rc = chat_setting_set(inst, name, value);
     if (rc == -1) { send_response(fd, id, NULL, "unknown setting"); return 0; }
     if (rc == -2) { send_response(fd, id, NULL, "invalid value"); return 0; }
     printf("control: chat_setting %s=%s\n", name, value);