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

src/utun_instance.h

@@ -99,6 +99,16 @@ struct utun_activity_cbk_entry {
     struct utun_activity_cbk_entry* next;
 };
 
+// Подписка на смену спячки пира (keepalive-протокол). Сервер (или любой узел)
+// получает от мобильного пира sleep-анонс и уведомляет подписчиков:
+// sleeping=1 — пир ушёл в спячку (в фон), 0 — проснулся (дедлайн истёк / обычный keepalive).
+typedef void (*peer_sleep_cbk_fn)(struct UTUN_INSTANCE* instance, uint64_t peer_node_id, int sleeping, void* arg);
+struct peer_sleep_cbk_entry {
+    peer_sleep_cbk_fn fn;
+    void*             arg;
+    struct peer_sleep_cbk_entry* next;
+};
+
 // uTun instance configuration
 struct UTUN_INSTANCE {
     // Identification
@@ -221,6 +231,7 @@ struct UTUN_INSTANCE {
     uint8_t  client_activity;          // CLIENT_ACTIVITY_STANDBY/ACTIVE
     void*    client_activity_timer;    // uasync timer handle for inactivity timeout
     struct utun_activity_cbk_entry* activity_cbks;  // подписки на смену client_activity
+    struct peer_sleep_cbk_entry*    peer_sleep_cbks; // подписки на смену спячки пира (keepalive)
     uint8_t  standby_enabled;          // 1 = standby duty-cycle активен (chatgui-android)
 
     // TCP proxy server (exit node)
@@ -259,6 +270,9 @@ void utun_instance_set_topo_group_enabled(int enabled);
 void utun_set_client_activity(struct UTUN_INSTANCE* instance, int active);
 void utun_add_activity_cbk(struct UTUN_INSTANCE* instance, utun_activity_cbk_fn fn, void* arg);
 void utun_remove_activity_cbk(struct UTUN_INSTANCE* instance, utun_activity_cbk_fn fn, void* arg);
+void utun_add_peer_sleep_cbk(struct UTUN_INSTANCE* instance, peer_sleep_cbk_fn fn, void* arg);
+void utun_remove_peer_sleep_cbk(struct UTUN_INSTANCE* instance, peer_sleep_cbk_fn fn, void* arg);
+void utun_fire_peer_sleep_cbk(struct UTUN_INSTANCE* instance, uint64_t peer_node_id, int sleeping);
 
 // Diagnostic function for memory leak analysis
 void utun_instance_diagnose_leaks(struct UTUN_INSTANCE* instance, const char* phase);