fix: listen socket CONNECT 不应触发 accepted 客户端逻辑

- WCHNET_HandleSockInt 第二路由条件增加 socketid!=g_json_socket_listen
- tcp_json_handle_sock_int 'Newly accepted' 检查增加 socketid!=g_json_socket_listen
- 防止 listen socket 的 CONNECT 事件误触发 WCHNET_ModifyRecvBuf 和 g_json_socket_client 覆写

根因：TCP_LISTEN socket 和 accepted client 是不同 socket ID（1 vs 3），
listen socket 的 CONNECT 不应穿透到 'newly accepted' 分支去配置 recv buffer，
否则会干扰 WCHNET 对 accepted socket 的数据路由

vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/net_srv.c

@@ -481,13 +481,15 @@ void WCHNET_HandleSockInt(uint8_t socketid, uint8_t intstat)
 {
     uint8_t i;
     
-    // Route JSON protocol socket events
+    // Route JSON protocol socket events (listen socket, client socket)
     if (socketid == g_json_socket_listen || socketid == g_json_socket_client) {
         tcp_json_handle_sock_int(socketid, intstat);
         return;
     }
     // Also catch newly accepted TCP connections that might be JSON clients
-    if ((intstat & SINT_STAT_CONNECT) && socketid != SocketId_TCP && socketid != SocketId_UDP) {
+    // Exclude: listen socket, SSC TCP, UDP
+    if ((intstat & SINT_STAT_CONNECT) && socketid != g_json_socket_listen
+        && socketid != SocketId_TCP && socketid != SocketId_UDP) {
         tcp_json_handle_sock_int(socketid, intstat);
         return;
     }

vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/tcp_json_srv.c

@@ -662,8 +662,9 @@ void tcp_json_handle_sock_int(uint8_t socketid, uint8_t intstat) {
         }
     }
 
-    // === Newly accepted client (CONNECT on unknown socket) ===
+    // === Newly accepted client (CONNECT on unknown socket, but NOT the listen socket) ===
     if ((intstat & SINT_STAT_CONNECT) && socketid != g_json_socket_client 
+        && socketid != g_json_socket_listen
         && socketid != SocketId_TCP && socketid != SocketId_UDP) {
         g_json_socket_client = socketid;
         g_json_auth_state = JSON_STATE_WAIT_AUTH;