transport: per-peer sleep callback (peer_sleep_cbk) fired from keepalive protocol

src/utun_instance.c

@@ -645,6 +645,12 @@ void utun_instance_destroy(struct UTUN_INSTANCE *instance) {
         instance->activity_cbks = r->next; u_free(r);
     }
 
+    // Cleanup peer-sleep callback chain
+    while (instance->peer_sleep_cbks) {
+        struct peer_sleep_cbk_entry* r = instance->peer_sleep_cbks;
+        instance->peer_sleep_cbks = r->next; u_free(r);
+    }
+
     // Shared SQLite DB закрываем в самом конце: routing/chat/media/db_sync
     // используют его во время всего teardown (см. topo_groups_destroy).
     if (instance->topo_sqlite_db) {
@@ -1130,6 +1136,35 @@ static void utun_fire_activity_cbk(struct UTUN_INSTANCE* instance, int active) {
     }
 }
 
+void utun_add_peer_sleep_cbk(struct UTUN_INSTANCE* instance, peer_sleep_cbk_fn fn, void* arg) {
+    if (!instance || !fn) return;
+    struct peer_sleep_cbk_entry* e = u_malloc(sizeof(*e));
+    if (!e) return;
+    e->fn = fn; e->arg = arg; e->next = instance->peer_sleep_cbks;
+    instance->peer_sleep_cbks = e;
+}
+
+void utun_remove_peer_sleep_cbk(struct UTUN_INSTANCE* instance, peer_sleep_cbk_fn fn, void* arg) {
+    if (!instance || !fn) return;
+    struct peer_sleep_cbk_entry** p = &instance->peer_sleep_cbks;
+    while (*p) {
+        if ((*p)->fn == fn && (*p)->arg == arg) {
+            struct peer_sleep_cbk_entry* rm = *p;
+            *p = rm->next; u_free(rm); return;
+        }
+        p = &(*p)->next;
+    }
+}
+
+void utun_fire_peer_sleep_cbk(struct UTUN_INSTANCE* instance, uint64_t peer_node_id, int sleeping) {
+    struct peer_sleep_cbk_entry* e = instance ? instance->peer_sleep_cbks : NULL;
+    while (e) {
+        struct peer_sleep_cbk_entry* n = e->next;
+        e->fn(instance, peer_node_id, sleeping, e->arg);
+        e = n;
+    }
+}
+
 static void client_activity_timeout_cb(void* arg) {
     struct UTUN_INSTANCE* instance = (struct UTUN_INSTANCE*)arg;
     DEBUG_INFO(DEBUG_CATEGORY_BGP, "client_activity_timer fired: node=%016llx type=%u -> standby",