Add AP+STA WiFi manager and stabilize balancing

- Replace wifi.cpp/wifi.h with wifi_manager.cpp/wifi_manager.h: AP and STA
  run together, external WiFi credentials are stored in NVS and editable at
  /wifi, with optional static IP, 15s auto-reconnect, disconnect reason
  reporting, and build/version diagnostics
- Fix MPU6050 I2C port to I2C0 to match the board wiring
- Initialize distance_zeropoint at startup and on Robot Go! rising edge
- Clamp angle_zeropoint to +/-10 degrees to prevent balance-point drift
- Add DEBUG_DISABLE_YAW switch and periodic balance debug output
- Update WiFi setup instructions in README.md and README_CN.md

3.Software/wl_pro_robot/wifi_manager.h

@@ -0,0 +1,35 @@
+// -----------------------------------------------------------------------------
+// Copyright (c) 2024 Mu Shibo
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+// -----------------------------------------------------------------------------
+
+#pragma once
+
+#include <WiFi.h>
+#include <WebServer.h>
+
+// 启动 AP 热点，并按 Flash 里保存的配置异步连接外部 WiFi（STA）
+void WiFi_Init(void);
+
+// 在主循环里调用：处理重连、串口状态打印、延时重启
+void WiFi_Loop(void);
+
+// 注册 /wifi 配置页面（需要在 webserver.begin() 之前调用）
+void WiFi_RegisterWebHandlers(WebServer &server);