feat(system): 优化微信小程序码获取接口，直接返回图片字节

- 修改getOrderQRCodeUnlimited接口，支持直接返回图片字节流
- 移除保存二维码图片到服务器文件的逻辑
- 在未登录时，通过响应码401返回错误提示
- 设置响应内容类型为image/png，禁用缓存，直接输出二维码图片数据
- 简化接口实现，提升性能与用户体验

src/main/java/com/gxwebsoft/common/system/controller/WxLoginController.java

@@ -35,7 +35,9 @@ import org.springframework.web.bind.annotation.*;
 
 import javax.annotation.Resource;
 import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 import java.io.File;
+import java.io.IOException;
 import java.util.HashMap;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
@@ -965,14 +967,16 @@ public class WxLoginController extends BaseController {
         return fail("获取失败", null);
     }
 
-    @Operation(summary = "获取微信小程序码-数量极多的业务场景（支持自定义页面与场景值）")
+    @Operation(summary = "获取微信小程序码-数量极多的业务场景（直接返回图片字节，支持自定义页面与场景值）")
     @GetMapping("/getOrderQRCodeUnlimited/{orderNo}")
-    public ApiResult<?> getOrderQRCodeUnlimited(@PathVariable("orderNo") String orderNo,
+    public void getOrderQRCodeUnlimited(@PathVariable("orderNo") String orderNo,
                                        @RequestParam(required = false) String page,
-                                               @RequestParam(required = false) String scene) {
+                                       @RequestParam(required = false) String scene,
+                                       HttpServletResponse response) throws IOException {
       final User loginUser = getLoginUser();
       if(loginUser == null){
-        return fail("请先登录");
+        response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "请先登录");
+        return;
       }
       String apiUrl = "https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=" + getAccessToken(loginUser.getTenantId());
         final HashMap<String, Object> map = new HashMap<>();
@@ -985,17 +989,12 @@ public class WxLoginController extends BaseController {
         byte[] qrCode = HttpRequest.post(apiUrl)
                 .body(JSON.toJSONString(map))
                 .execute().bodyBytes();
-        System.out.println("qrCode = " + qrCode);
 
-        // 保存的文件名称
-        final String fileName = CommonUtil.randomUUID8().concat(".png");
-        // 保存路径
-        String filePath = getUploadDir().concat("qrcode/") + fileName;
-        File file = FileUtil.writeBytes(qrCode, filePath);
-        if (file != null) {
-            return success(config.getFileServer().concat("/qrcode/").concat(fileName));
-        }
-        return fail("获取失败", null);
+        // 直接将小程序码图片字节写回响应，不依赖 file.websoft.top 文件服务器
+        response.setContentType("image/png");
+        response.setHeader("Cache-Control", "no-cache");
+        response.getOutputStream().write(qrCode);
+        response.getOutputStream().flush();
     }