fix(nat): advance after an unfinished pair uses its full retry budget

src/routing_layer/nat_detection.c

@@ -70,7 +70,7 @@ struct nat_socket {
     uint8_t contacts[NAT_MAX_CONTACTS][17];
     unsigned contact_count, contact_cutoff, cycle_contact_cutoff, phase, reason, retries;
     uint8_t history_loaded, history_complete, history_incomplete, filter_clean, pre_received, post_received, pre_healthy;
-    uint8_t cycle_history_complete, cycle_mapping_seen;
+    uint8_t cycle_history_complete, cycle_mapping_seen, pair_full_budget;
     uint8_t helper_socket, active_ping, heartbeat_active, forced, cycling;
     uint32_t rounds, helper_reselections;
 };
@@ -641,6 +641,11 @@ static void remember_address(struct nat_socket *state, const struct sockaddr_sto
 }
 
 static void owner_finish(struct nat_socket *state, uint8_t reason) {
+    if (reason == NAT_REASON_BUDGET && state->pair_full_budget) {
+        reason = NAT_REASON_TIMEOUT;
+        DEBUG_WARN(DEBUG_CATEGORY_NAT, "NAT pair full budget exhausted socket=%s round=%016llx; advancing candidate",
+                   state->socket->name, (unsigned long long)state->round);
+    }
     /* Неудача входящего испытания не мешает сравнить mapping через уже известный публичный endpoint C. */
     if ((reason == NAT_REASON_TIMEOUT || reason == NAT_REASON_CONTROL_LOST || reason == NAT_REASON_SEND_ERROR ||
          reason == NAT_REASON_CONTACT_HISTORY) &&
@@ -1279,6 +1284,7 @@ static void owner_start(struct nat_socket *state) {
     }
     uint64_t now = get_time_tb();
     history_load(state);
+    int full_budget = !state->cycling || now >= state->cycle_deadline;
     if (!state->cycling) {
         state->cycling = 1; state->cursor = (struct nat_pair){0};
         state->cycle_contact_cutoff = state->contact_count; state->cycle_history_complete = state->history_complete;
@@ -1290,6 +1296,7 @@ static void owner_start(struct nat_socket *state) {
                    state->socket->name, state->cycle_contact_cutoff, state->contact_count);
     }
     if (select_pair(state)) { owner_finish(state, state->reason); return; }
+    state->pair_full_budget = full_budget;
     if (random_id(&state->round)) { owner_finish(state, NAT_REASON_SEND_ERROR); return; }
     state->rounds++;
     memset(&state->helper_seen, 0, sizeof(state->helper_seen)); memset(&state->baseline, 0, sizeof(state->baseline));