etcp: INFO-level TX DATA log + Initial packet received log

- 1133: DEBUG_DEBUG -> DEBUG_INFO for TX DATA (seq, len, retry, queue lengths)
- 1437: add DEBUG_INFO when initial packet seq=1 accepted

These two INFO lines show the exact order of first sends and receives
to diagnose INIT sequencer sync without guessing.

src/etcp.c

@@ -1130,7 +1130,7 @@ struct ETCP_DGRAM* etcp_request_pkt(struct ETCP_CONN* etcp) {
             }
         }
         // фрейм data (0) обязательно в конец
-        DEBUG_DEBUG(DEBUG_CATEGORY_ETCP, "[%s] TX DATA: seq=%u len=%u retry=%d; Qlen: in=%d snd=%d wait=%d", etcp->log_name, inf_pkt->seq, inf_pkt->ll.len, inf_pkt->send_count, etcp->input_queue->count, etcp->input_send_q->count, etcp->input_wait_ack->count);
+        DEBUG_INFO(DEBUG_CATEGORY_ETCP, "[%s] TX DATA: seq=%u len=%u retry=%d; Qlen: in=%d snd=%d wait=%d", etcp->log_name, inf_pkt->seq, inf_pkt->ll.len, inf_pkt->send_count, etcp->input_queue->count, etcp->input_send_q->count, etcp->input_wait_ack->count);
 
         dgram->data[ptr++]=0;// payload
         dgram->data[ptr++]=inf_pkt->seq;
@@ -1434,7 +1434,7 @@ void etcp_conn_input(struct ETCP_DGRAM* pkt) {
                     // формируем ACK
                     uint32_t seq=data[1] | (data[2]<<8) |  (data[3]<<16) |  (data[4]<<24);
                     if (etcp->got_initial_pkt == 0) {
-                        if (seq==1) etcp->got_initial_pkt = 1;
+                        if (seq==1) { etcp->got_initial_pkt = 1; DEBUG_INFO(DEBUG_CATEGORY_ETCP, "[%s] Initial packet seq=1 received", etcp->log_name); }
                         else {
                             DEBUG_WARN(DEBUG_CATEGORY_ETCP, "[%s] Waiting for initial packet but recv seq=%d, ignoring", etcp->log_name, seq);
                             len=0;