fix: UDP packet size and addr_type classification

- etcp_connections.h: add WIRE_OVERHEAD, IP_UDP_OVERHEAD_V4/V6, SC_ENCRYPT_OVERHEAD
  (properly accounts for v6 IP(40)+UDP(8)+SC(3)+CCM tag(16) = 67 vs old UDP_HDR_SIZE=28)
- etcp_connections.c etcp_encrypt_send: use WIRE_OVERHEAD instead of UDP_HDR_SIZE
- etcp_connections.c send_init_response: clamp padding to max_data = mtu - WIRE_OVERHEAD
- chat_core_priv.h: add addr_type_from_ip() classifier
- chat_profile.c, chat_sync.c, member_sync.c: use classified addr_type instead of hardcoded 0
- chat_sync.c: skip zero nat_addr in JOIN, fall back to interface_addr
- topo_node_sqlite.c, member_sync.c: remove addr_type=0 filter from SELECT/DELETE
- chat_profile.c, member_sync.c: DELETE all addresses (not just addr_type=0)

src/routing_layer/topo_node_sqlite.c

@@ -383,7 +383,7 @@ int topo_node_sqlite_channel_peers_all(sqlite3* db, const char* channel_id,
         sqlite3_stmt* ast = NULL;
         snprintf(sql, sizeof(sql),
             "SELECT family, socket_id, protocol, address, port FROM node_addresses"
-            " WHERE node_id=? AND addr_type=0 LIMIT 16");
+            " WHERE node_id=? LIMIT 16");
         if (sqlite3_prepare_v2(db, sql, -1, &ast, NULL) != SQLITE_OK) continue;
         sqlite3_bind_int64(ast, 1, (sqlite3_int64)node_id);