fix: revert etcp_link_update_inflight_lim + BBR callback in etcp_link_new

52f32da replaced direct inflight_lim_bytes assignment and inline
optimal_inflight recalculation with etcp_link_update_inflight_lim()
+ BBR on_cwnd_update callback. This broke test_etcp_reconnect
(flaky FAIL in phase 4, recv=0 after server restart).

Revert etcp_connections.c/h back to inline init. Keep BBR callback
infrastructure (etcp_bbr.c/h) and IPv6/sockaddr changes
(config_parser, utun_instance) which are harmless.

src/etcp_connections.c

@@ -746,8 +746,6 @@ void etcp_socket_remove(struct ETCP_SOCKET* conn) {
 }
 
 
-static void bbr_cwnd_updated(void* ctx, uint32_t new_cwnd);
-
 struct ETCP_LINK* etcp_link_new(struct ETCP_CONN* etcp, struct ETCP_SOCKET* conn, struct sockaddr_storage* remote_addr, uint8_t is_server) {
     DEBUG_TRACE(DEBUG_CATEGORY_CONNECTION, "");
     if (!remote_addr) return NULL;
@@ -833,9 +831,12 @@ struct ETCP_LINK* etcp_link_new(struct ETCP_CONN* etcp, struct ETCP_SOCKET* conn
     while (l && l->next) l=l->next;
     if (l) l->next = link; else etcp->links = link;
 
-    etcp_link_update_inflight_lim(link, link->mtu * 4);
-    link->bbr->on_cwnd_update = bbr_cwnd_updated;
-    link->bbr->cwnd_update_ctx = link;
+    link->inflight_lim_bytes = link->mtu * 4;     // BBR init_cwnd (~4 packets)
+
+// пересчитать connection-level optimal_inflight
+    {   uint32_t sum = 0;
+        for (struct ETCP_LINK* tl = etcp->links; tl; tl = tl->next) sum += tl->inflight_lim_bytes;
+        etcp->optimal_inflight = sum; }
 
     DEBUG_INFO(DEBUG_CATEGORY_CONNECTION, "NEW link initialized on etcp=[%s] link=%p socket=%s id=%d is_server=%d mtu=%d", etcp->log_name, link, conn->name, link->local_link_id, link->is_server, link->mtu);
 
@@ -847,18 +848,6 @@ struct ETCP_LINK* etcp_link_new(struct ETCP_CONN* etcp, struct ETCP_SOCKET* conn
     return link;
 }
 
-static void bbr_cwnd_updated(void* ctx, uint32_t new_cwnd) {
-    etcp_link_update_inflight_lim((struct ETCP_LINK*)ctx, new_cwnd);
-}
-
-void etcp_link_update_inflight_lim(struct ETCP_LINK* link, uint32_t new_lim) {
-    link->inflight_lim_bytes = new_lim;
-    struct ETCP_CONN* etcp = link->etcp;
-    uint32_t sum = 0;
-    for (struct ETCP_LINK* tl = etcp->links; tl; tl = tl->next) sum += tl->inflight_lim_bytes;
-    etcp->optimal_inflight = sum;
-}
-
 void etcp_link_close(struct ETCP_LINK* link) {
     DEBUG_TRACE(DEBUG_CATEGORY_CONNECTION, "");
     if (!link) return;

src/etcp_connections.h

@@ -262,7 +262,6 @@ void etcp_socket_remove(struct ETCP_SOCKET* conn);
 // connection functions
 // создает новый канал связи для etcp подключения (ETCP_CONN)
 struct ETCP_LINK* etcp_link_new(struct ETCP_CONN* etcp, struct ETCP_SOCKET* conn, struct sockaddr_storage* remote_addr, uint8_t is_server);
-void etcp_link_update_inflight_lim(struct ETCP_LINK* link, uint32_t new_lim);
 void etcp_link_close(struct ETCP_LINK* link);
 //int etcp_input_cbk(struct packet_buffer* pkt, struct ETCP_SOCKET* conn);// получает расшифрованный пакет
 int etcp_encrypt_send(struct ETCP_DGRAM* dgram);// зашифровывает и отправляет пакет