debug: add diagnostic logging for ETCP recv/INIT/dispatch paths

- etcp_connections.c: raw_recv log, INIT conn lookup details, insert_link DUP details
- etcp_api.c: dispatch id/cb logs with DROPPED warning when no handler
- chat_sync.c: etcp_send rc log, fix ac_result_cb to always clear ca_state

src/etcp_api.c

@@ -102,10 +102,12 @@ void etcp_int_recv(struct ll_queue* queue, void* arg) {
     uint8_t id = e->dgram[0];
     struct UTUN_INSTANCE* inst = conn->instance;
     if (!inst) { queue_dgram_free(e); queue_entry_free(e); queue_resume_callback(queue); return; }
-    if (inst->api_bindings.callbacks[id])
+    if (inst->api_bindings.callbacks[id]) {
+        DEBUG_DEBUG(DEBUG_CATEGORY_DEBUG, "dispatch id=0x%02x conn=%s len=%zu", id, conn->log_name, e->len);
         inst->api_bindings.callbacks[id](conn, e);
-    else if (inst->api_bindings.callbacks[0])
+    } else if (inst->api_bindings.callbacks[0]) {
+        DEBUG_DEBUG(DEBUG_CATEGORY_DEBUG, "dispatch id=0x%02x (fallback) conn=%s len=%zu", id, conn->log_name, e->len);
         inst->api_bindings.callbacks[0](conn, e);
-    else { queue_dgram_free(e); queue_entry_free(e); }
+    } else { DEBUG_DEBUG(DEBUG_CATEGORY_DEBUG, "dispatch id=0x%02x NO CB conn=%s len=%zu — DROPPED", id, conn->log_name, e->len); queue_dgram_free(e); queue_entry_free(e); }
     queue_resume_callback(queue);
 }

src/etcp_connections.c

@@ -398,7 +398,14 @@ static int insert_link(struct ETCP_SOCKET* e_sock, struct ETCP_LINK* link) {
     }
     
     int idx = find_link_index(e_sock, link->ip_port_hash);
-    if (idx >= 0) return -1;
+    if (idx >= 0) {
+        DEBUG_DEBUG(DEBUG_CATEGORY_DEBUG, "insert_link DUP: hash=0x%08x idx=%d existing_conn=%s existing_etcp=%s num_channels=%zu sock=%s",
+                    link->ip_port_hash, idx,
+                    e_sock->links[idx]->etcp ? e_sock->links[idx]->etcp->log_name : "?",
+                    e_sock->links[idx]->etcp ? "[...]" : "?",
+                    e_sock->num_channels, e_sock->name);
+        return -1;
+    }
     
     idx = -(idx + 1);
     
@@ -1525,6 +1532,8 @@ void etcp_connections_read_callback_socket(socket_t sock, void* arg) {
         return;
     }
 
+    DEBUG_DEBUG(DEBUG_CATEGORY_DEBUG, "raw_recv on %s from=%s len=%zd", e_sock->name, sockaddr_storage_to_str(&addr).str, recv_len);
+
     // DUMP: Show received packet content
     if (debug_should_output(DEBUG_LEVEL_DEBUG, DEBUG_CATEGORY_CRYPTO)) log_dump(DEBUG_LEVEL_DEBUG, DEBUG_CATEGORY_CRYPTO, "RECV in:", data, recv_len);
 
@@ -1705,6 +1714,8 @@ void etcp_connections_read_callback_socket(socket_t sock, void* arg) {
         if (memcmp(conn->crypto_ctx.peer_public_key, sc.peer_public_key, SC_PUBKEY_SIZE)) { errorcode=5; DEBUG_ERROR(DEBUG_CATEGORY_CRYPTO, "peer key mismatch for node %016llx", (unsigned long long)peer_id); goto ec_fr; }// коллизия - peer id совпал а ключи разные.
         }
 
+    DEBUG_DEBUG(DEBUG_CATEGORY_DEBUG, "INIT conn=%s new_conn=%d peer=0x%016llx state=%d links_up=%d links=%p", conn->log_name, new_conn, (unsigned long long)peer_id, conn->state, conn->links_up, (void*)conn->links);
+
     // Check if link already exists (for CHANNEL_INIT recovery)
 
     struct ETCP_LINK* existing_link = etcp_link_find_by_remote_id(conn, req->link_id);