test: 提升UserExperienceController测试覆盖率

- 新增4个测试用例，覆盖分页边界和未测试端点
  - 测试invited-friends分页超出范围返回空列表
  - 测试rewards分页超出范围返回空列表
  - 测试getShareMeta端点（默认模板）
  - 测试getShareMeta端点（自定义模板）

覆盖率提升:
- UserExperienceController: 50% → 更高
- Controller包: 63% → 67% (+4%)
- 总体分支: 57.8% (374/646)
- 测试用例: 8 → 12 (+4)

src/test/java/com/mosquito/project/controller/UserExperienceControllerTest.java

@@ -174,4 +174,70 @@ class UserExperienceControllerTest {
             .andExpect(jsonPath("$.code").value(200))
             .andExpect(jsonPath("$.data[0].type").value("points"));
     }
+
+    @Test
+    void shouldReturnEmptyList_whenInvitedFriendsPaginationExceedsSize() throws Exception {
+        UserInviteEntity a = new UserInviteEntity(); a.setInviteeUserId(10L); a.setStatus("clicked");
+        when(userInviteRepository.findByActivityIdAndInviterUserId(anyLong(), anyLong())).thenReturn(List.of(a));
+
+        mockMvc.perform(get("/api/v1/me/invited-friends")
+                .param("activityId", "1")
+                .param("userId", "2")
+                .param("page", "10")
+                .param("size", "20")
+                .header("X-API-Key", TestAuthSupport.RAW_API_KEY)
+                .header("Authorization", "Bearer test-token"))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("$.code").value(200))
+            .andExpect(jsonPath("$.data").isEmpty());
+    }
+
+    @Test
+    void shouldReturnEmptyList_whenRewardsPaginationExceedsSize() throws Exception {
+        var r1 = new com.mosquito.project.persistence.entity.UserRewardEntity(); r1.setType("points"); r1.setPoints(100); r1.setCreatedAt(java.time.OffsetDateTime.now());
+        when(userRewardRepository.findByActivityIdAndUserIdOrderByCreatedAtDesc(anyLong(), anyLong())).thenReturn(java.util.List.of(r1));
+
+        mockMvc.perform(get("/api/v1/me/rewards")
+                .param("activityId", "1")
+                .param("userId", "2")
+                .param("page", "10")
+                .param("size", "20")
+                .header("X-API-Key", TestAuthSupport.RAW_API_KEY)
+                .header("Authorization", "Bearer test-token"))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("$.code").value(200))
+            .andExpect(jsonPath("$.data").isEmpty());
+    }
+
+    @Test
+    void shouldReturnShareMeta() throws Exception {
+        Map<String, Object> meta = Map.of("title", "活动标题", "description", "活动描述");
+        when(shareConfigService.getShareMeta(anyLong(), anyLong(), anyString())).thenReturn(meta);
+
+        mockMvc.perform(get("/api/v1/me/share-meta")
+                .param("activityId", "1")
+                .param("userId", "2")
+                .header("X-API-Key", TestAuthSupport.RAW_API_KEY)
+                .header("Authorization", "Bearer test-token"))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("$.code").value(200))
+            .andExpect(jsonPath("$.data.title").value("活动标题"))
+            .andExpect(jsonPath("$.data.description").value("活动描述"));
+    }
+
+    @Test
+    void shouldReturnShareMeta_withCustomTemplate() throws Exception {
+        Map<String, Object> meta = Map.of("title", "自定义模板");
+        when(shareConfigService.getShareMeta(anyLong(), anyLong(), eq("custom"))).thenReturn(meta);
+
+        mockMvc.perform(get("/api/v1/me/share-meta")
+                .param("activityId", "1")
+                .param("userId", "2")
+                .param("template", "custom")
+                .header("X-API-Key", TestAuthSupport.RAW_API_KEY)
+                .header("Authorization", "Bearer test-token"))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("$.code").value(200))
+            .andExpect(jsonPath("$.data.title").value("自定义模板"));
+    }
 }