fix(分页): MybatisPlusConfig 缺少 PaginationInnerInterceptor 导致 selectPage 不分页

PaginationInnerInterceptor 负责为 selectPage 生成 LIMIT/COUNT 查询，
缺失时返回全部记录且 total=0，前端分页控件因此不显示。

src/main/java/com/guo/learningprogresstracker/config/MybatisPlusConfig.java

@@ -3,6 +3,7 @@ package com.guo.learningprogresstracker.config;
 import cn.dev33.satoken.stp.StpUtil;
 import net.sf.jsqlparser.expression.StringValue;
 import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
+import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
 import com.baomidou.mybatisplus.extension.plugins.inner.TenantLineInnerInterceptor;
 import com.baomidou.mybatisplus.extension.plugins.handler.TenantLineHandler;
 import net.sf.jsqlparser.expression.Expression;
@@ -33,6 +34,8 @@ public class MybatisPlusConfig {
     @Bean
     public MybatisPlusInterceptor mybatisPlusInterceptor() {
         MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
+        // 分页拦截器必须注册，否则 selectPage 不会生成 LIMIT / COUNT
+        interceptor.addInnerInterceptor(new PaginationInnerInterceptor());
         interceptor.addInnerInterceptor(new TenantLineInnerInterceptor(new TenantLineHandler() {
             @Override
             public Expression getTenantId() {