feat: TCP协议支持protobuf序列化，保留JSON兼容

- 新增 tcp_messages_pb2.py protobuf Python绑定
- msg_handler.cpp: 新增 make_packet_pb/raw bytes打包, parse_packet_raw/raw解析
- archery_netcore.cpp: 注册 make_packet_pb/parse_packet_raw
- network.py: 新增 _use_proto 标志，_make_send_packet/_parse_recv 自动选择proto/JSON
- 登录version加+proto后缀标识proto模式
- protobuf序列化/反序列化失败时自动回退JSON

cpp_ext/msg_handler.cpp

@@ -51,6 +51,43 @@ namespace netcore {
         return py::bytes(reinterpret_cast<const char*>(packet.data()), packet.size());
     }
 
+    // 打包 TCP 数据包 (raw bytes body, 用于 protobuf)
+    py::bytes make_packet_pb(int msg_type, py::bytes body_bytes) {
+        netcore::log_debug(std::string("make_packet_pb msg_type=") + std::to_string(msg_type));
+
+        py::buffer_info buf = py::buffer(body_bytes).request();
+        uint32_t body_len = buf.size;
+        uint32_t checksum = body_len + msg_type;
+
+        std::vector<uint8_t> packet;
+        packet.reserve(12 + body_len);
+
+        // body_len (big-endian, 4 bytes)
+        packet.push_back((body_len >> 24) & 0xFF);
+        packet.push_back((body_len >> 16) & 0xFF);
+        packet.push_back((body_len >> 8) & 0xFF);
+        packet.push_back(body_len & 0xFF);
+
+        // msg_type (big-endian, 4 bytes)
+        packet.push_back((msg_type >> 24) & 0xFF);
+        packet.push_back((msg_type >> 16) & 0xFF);
+        packet.push_back((msg_type >> 8) & 0xFF);
+        packet.push_back(msg_type & 0xFF);
+
+        // checksum (big-endian, 4 bytes)
+        packet.push_back((checksum >> 24) & 0xFF);
+        packet.push_back((checksum >> 16) & 0xFF);
+        packet.push_back((checksum >> 8) & 0xFF);
+        packet.push_back(checksum & 0xFF);
+
+        // 追加 body bytes
+        const uint8_t* body_ptr = static_cast<const uint8_t*>(buf.ptr);
+        packet.insert(packet.end(), body_ptr, body_ptr + body_len);
+
+        netcore::log_debug(std::string("make_packet_pb done bytes=") + std::to_string(packet.size()));
+        return py::bytes(reinterpret_cast<const char*>(packet.data()), packet.size());
+    }
+
     // 解析 TCP 数据包
     py::tuple parse_packet(py::bytes data) {
         // 1) 转换为 bytes view
@@ -110,4 +147,26 @@ namespace netcore {
             return py::make_tuple(py::int_(msg_type), raw_dict);
         }
     }
+
+    // 解析 TCP 数据包 -> (msg_type, body_bytes) 不做 JSON 解析
+    py::tuple parse_packet_raw(py::bytes data) {
+        py::buffer_info buf = py::buffer(data).request();
+        if (buf.size < 12) {
+            return py::make_tuple(py::none(), py::none());
+        }
+
+        const uint8_t* ptr = static_cast<const uint8_t*>(buf.ptr);
+
+        uint32_t body_len = (ptr[0] << 24) | (ptr[1] << 16) | (ptr[2] << 8) | ptr[3];
+        uint32_t msg_type = (ptr[4] << 24) | (ptr[5] << 16) | (ptr[6] << 8) | ptr[7];
+
+        uint32_t expected_len = 12 + body_len;
+        if (buf.size < expected_len) {
+            return py::make_tuple(py::none(), py::none());
+        }
+
+        // 返回原始 body bytes（不做 JSON 解析）
+        py::bytes body_bytes(reinterpret_cast<const char*>(ptr + 12), body_len);
+        return py::make_tuple(py::int_(msg_type), body_bytes);
+    }
 }