feat(invite): 新增H5邀请链接配置与返回

在 AppConfig 中增加 inviteConfig 及 h5Link 字段；
服务层改造 getUserInviteCode 返回 InviteCodeRespVO 并填充 h5Link；
Controller 简化调用逻辑，统一走服务层组装 VO。

src/main/java/com/yolo/keyborad/controller/UserController.java

@@ -143,11 +143,6 @@ public class UserController {
     @Operation(summary = "查询邀请码", description = "查询用户自己的邀请码")
     public BaseResponse<InviteCodeRespVO> getInviteCode() {
         long userId = StpUtil.getLoginIdAsLong();
-        KeyboardUserInviteCodes inviteCode = inviteCodesService.getUserInviteCode(userId);
-        if (inviteCode == null) {
-            inviteCode = inviteCodesService.createInviteCode(userId);
-        }
-        InviteCodeRespVO respVO = BeanUtil.copyProperties(inviteCode, InviteCodeRespVO.class);
-        return ResultUtils.success(respVO);
+        return ResultUtils.success( inviteCodesService.getUserInviteCode(userId));
     }
 }