refactor: 代码优化

src/main/java/com/youlai/system/controller/AuthController.java

@@ -41,7 +41,7 @@ public class AuthController {
 
     @Operation(summary = "获取验证码")
     @GetMapping("/captcha")
-    public Result getCaptcha() {
+    public Result<CaptchaResult> getCaptcha() {
         CaptchaResult captcha = authService.getCaptcha();
         return Result.success(captcha);
     }