stcp: ed25519 pubkey exchange in handshake, fix instance destroy segfault, fix chat_tcp_test

- u_async.c: process immediate_queue BEFORE epoll_wait in uasync_poll
- stcp_link.c: defensive NULL etcp_conn/etcp_link in stcp_link_close
- utun_instance.c: move stcp_server_list_destroy_all to Phase J (before ETCP),
  add deferred drain in both Phase J and L
- stcp.h/c: STCP_HS_ENC_CLIENT 6→38, STCP_HS_ENC_SERVER 7→39,
  exchange ed25519_pubkey in both handshake directions
- etcp_connections.c: copy peer_ed25519 from STCP to ETCP_CONN in
  etcp_link_enter_ready_tcp; guard link->etcp in tcp_link_close_cb
- chat_sync.c: fix lk->conn NULL dereference for TCP links
- test_stcp.c: update stcp_server_create/stcp_client_connect callsites
- tools/chat_tcp_test: change transport udp→tcp

src/routing_layer/topo_node_sqlite.h

@@ -0,0 +1,75 @@
+#ifndef TOPO_NODE_SQLITE_H
+#define TOPO_NODE_SQLITE_H
+
+#include <sqlite3.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <time.h>
+#include "topo_node.h"
+
+#define PEERS_JOIN_SIG_SIZE   64
+#define PEERS_JOIN_TS_SIZE     8
+#define PEERS_UPDATE_SIG_SIZE  64
+
+/* flags byte in wire format */
+#define PEERS_FLAG_HAS_JOIN  0x01
+
+int topo_node_sqlite_init(sqlite3* db);
+
+int topo_node_sqlite_node_put(sqlite3* db, struct TOPO_GROUPS* groups, struct TOPO_GROUP_NODE* nq, time_t now_sec);
+
+int topo_node_sqlite_channel_put(sqlite3* db, const char* channel_id,
+    const char* name, uint64_t owner_node_id,
+    const uint8_t* x25519_pub, const uint8_t* x25519_priv,
+    const uint8_t* ed25519_pub, const uint8_t* ed25519_priv,
+    const uint8_t* signature);
+
+int topo_node_sqlite_member_put(sqlite3* db, const char* channel_id, uint64_t node_id,
+    const uint8_t* join_sig, uint64_t join_ts,
+    const uint8_t* update_sig, uint64_t update_ts,
+    const uint8_t* x25519_pubkey, const uint8_t* ed25519_pubkey, const char* userinfo,
+    const uint8_t* creator_sig,
+    const char* adm_tags, const uint8_t* adm_tags_sig, int storage);
+
+int topo_node_sqlite_member_get_join(sqlite3* db, const char* channel_id, uint64_t node_id,
+    uint8_t* join_sig_out, uint64_t* join_ts_out);
+
+int topo_node_sqlite_member_del(sqlite3* db, const char* channel_id, uint64_t node_id);
+
+int topo_node_sqlite_node_update_verified(sqlite3* db, uint64_t node_id,
+    const char* name, const uint8_t* x25519, const uint8_t* ed25519, uint64_t update_ts, time_t created_at);
+
+int topo_node_sqlite_channel_get(sqlite3* db, const char* channel_id,
+    char* name_out, int name_sz, uint64_t* owner_node_id,
+    uint8_t* x25519_pub, uint8_t* ed25519_pub, uint8_t* signature);
+
+int topo_node_sqlite_channel_peers_all(sqlite3* db, const char* channel_id,
+    uint8_t* buf, size_t buf_sz, size_t* out_len);
+
+int topo_node_sqlite_node_set_online(sqlite3* db, uint64_t node_id, int online);
+int topo_node_sqlite_node_get_online(sqlite3* db, uint64_t node_id);
+int topo_node_sqlite_get_ed25519_pubkey(sqlite3* db, uint64_t node_id, uint8_t pubkey_out[32]);
+
+/** Пересчитывает node_type во всех peers_* таблицах на основе addr_type из node_addresses */
+int topo_node_sqlite_nodeinfo_updated(sqlite3* db, uint64_t node_id);
+
+/** Обновляет RTT узла: node_addresses.rtt и все peers_*.node_RTT */
+void topo_node_sqlite_update_rtt(sqlite3* db, uint64_t node_id, uint16_t rtt);
+
+/**
+ * @brief Загружает TOPO_NODE из SQLite (ref_count=0).
+ * @param groups нужен для выделения адресов из memory_pool
+ * @return TOPO_NODE* или NULL если узел не найден/нет адресов
+ *
+ * Загружает pubkey, name из nodes, IPv4/UDP-адреса из node_addresses.
+ * Вызывающий должен передать владение через topo_node_registry_acquire().
+ */
+struct TOPO_NODE* topo_node_sqlite_node_load(sqlite3* db, struct TOPO_GROUPS* groups, uint64_t node_id);
+
+int topo_node_sqlite_set_connected(sqlite3* db, const char* channel_id, uint64_t node_id, int connected);
+int topo_node_sqlite_get_connected_peers(sqlite3* db, const char* channel_id, uint64_t** out_ids, int* out_count);
+int topo_node_sqlite_get_public_peers(sqlite3* db, const char* channel_id, uint64_t** out_ids, int* out_count, uint64_t self_node_id);
+int topo_node_sqlite_get_local_peers(sqlite3* db, const char* channel_id, uint64_t** out_ids, int* out_count, uint64_t self_node_id);
+int topo_node_sqlite_get_supernode_peers(sqlite3* db, const char* channel_id, uint64_t** out_ids, int* out_count);
+
+#endif