Schedule member sync when joining over an existing transport

src/chat/chat_sync.c

@@ -1420,6 +1420,10 @@ static void cs_handle_join_request(struct chat_sync* cs, uint64_t peer,
 
     cs_refresh_channels(cs);
     cs_post_channel_online(cs, ch_id);
+    /* Новый канал может использовать уже открытый транспорт: события conn_up не будет. */
+    cs_schedule_sync(cs);
+    DEBUG_DEBUG(DEBUG_CATEGORY_MEMBER_SYNC, "%s: JOIN_REQUEST schedule member sync ch=%s peer=%016llx",
+                CS_ID, ch_id, (unsigned long long)peer);
 }
 
 /* ─── JOIN_READY (0x13): connection-узел → joiner (можно запускать BGP) ─── */
@@ -1441,6 +1445,10 @@ static void cs_handle_join_ready(struct chat_sync* cs, uint64_t peer,
         }
     }
     chat_core_ensure_channel_ready(cs->inst, ch_id);
+    cs_refresh_channels(cs);
+    cs_schedule_sync(cs);
+    DEBUG_DEBUG(DEBUG_CATEGORY_MEMBER_SYNC, "%s: JOIN_READY schedule member sync ch=%s peer=%016llx",
+                CS_ID, ch_id, (unsigned long long)peer);
 
     uint8_t evt[65]; uint8_t ch_id_len = (uint8_t)strlen(ch_id);
     evt[0] = ch_id_len; memcpy(evt + 1, ch_id, ch_id_len);