feat(pigx-mp-platform): 新增按wxUserId精确过滤微信消息查询

- 分页查询新增 wxUserId 精确匹配条件，字段为空时不参与过滤
- 更新接口注释，明确各过滤字段的匹配规则
- 新增 WxFansMsgControllerTests 单元测试，验证按公众号和粉丝维度过滤

(cherry picked from commit 66870cc38f44ccc6c116a09c5e5620ac4b43f9b3)

pigx-visual/pigx-mp-platform/src/main/java/com/pig4cloud/pigx/mp/controller/WxFansMsgController.java

@@ -16,6 +16,7 @@
  */
 package com.pig4cloud.pigx.mp.controller;
 
+import cn.hutool.core.util.ObjectUtil;
 import cn.hutool.core.util.StrUtil;
 import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
 import com.baomidou.mybatisplus.core.toolkit.Wrappers;
@@ -43,14 +44,16 @@ public class WxFansMsgController {
 	private final WxMsgService wxMsgService;
 
 	/**
-	 * 分页查询
+	 * 分页查询微信消息，可按公众号、粉丝、昵称和消息类型过滤
 	 * @param page 分页对象
-	 * @param msg 查询条件
+	 * @param msg 查询条件：appId、wxUserId、type 精确匹配，nickName 模糊匹配；字段为空时不参与过滤
+	 * @return 消息分页结果
 	 */
 	@GetMapping("/page")
 	public R getWxMsgPage(Page page, WxMsg msg) {
 		LambdaQueryWrapper<WxMsg> wrapper = Wrappers.<WxMsg>lambdaQuery()
 			.eq(StrUtil.isNotBlank(msg.getAppId()), WxMsg::getAppId, msg.getAppId())
+			.eq(ObjectUtil.isNotNull(msg.getWxUserId()), WxMsg::getWxUserId, msg.getWxUserId())
 			.like(StrUtil.isNotBlank(msg.getNickName()), WxMsg::getNickName, msg.getNickName())
 			.eq(StrUtil.isNotBlank(msg.getType()), WxMsg::getType, msg.getType());
 		return R.ok(wxMsgService.page(page, wrapper));

pigx-visual/pigx-mp-platform/src/test/java/com/pig4cloud/pigx/mp/controller/WxFansMsgControllerTests.java

@@ -0,0 +1,40 @@
+package com.pig4cloud.pigx.mp.controller;
+
+import com.baomidou.mybatisplus.core.MybatisConfiguration;
+import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
+import com.baomidou.mybatisplus.core.metadata.TableInfoHelper;
+import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
+import com.pig4cloud.pigx.mp.entity.WxMsg;
+import com.pig4cloud.pigx.mp.service.WxMsgService;
+import org.apache.ibatis.builder.MapperBuilderAssistant;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.same;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+class WxFansMsgControllerTests {
+
+	@Test
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	void conversationQueryRestrictsMessagesToAccountAndFan() {
+		TableInfoHelper.initTableInfo(new MapperBuilderAssistant(new MybatisConfiguration(), "test"), WxMsg.class);
+		WxMsgService service = mock(WxMsgService.class);
+		WxFansMsgController controller = new WxFansMsgController(service);
+		WxMsg filter = new WxMsg();
+		filter.setAppId("test-account");
+		filter.setWxUserId(42L);
+		Page<WxMsg> page = new Page<>(1, 20);
+
+		controller.getWxMsgPage(page, filter);
+
+		ArgumentCaptor<LambdaQueryWrapper<WxMsg>> captor = ArgumentCaptor.forClass(LambdaQueryWrapper.class);
+		verify(service).page(same(page), captor.capture());
+		LambdaQueryWrapper<WxMsg> query = captor.getValue();
+		assertThat(query.getSqlSegment()).contains("app_id =", "wx_user_id =");
+		assertThat(query.getParamNameValuePairs()).containsValues("test-account", 42L);
+	}
+
+}