feat: 清理示例数据并统一空态体验

frontend/src/views/fees/ContractFees.vue

@@ -164,8 +164,10 @@
               </el-button>
             </template>
           </el-table-column>
+          <template #empty>
+            <div class="table-empty">{{ TEXT.modules.feeContracts.empty }}</div>
+          </template>
         </el-table>
-        <StateEmpty v-if="sortedContracts.length === 0" :description="TEXT.modules.feeContracts.empty" />
       </section>
     </div>
   </div>
@@ -181,7 +183,6 @@ import { fetchSites } from "../../api/sites";
 import { useStudyStore } from "../../store/study";
 import { usePermission } from "../../utils/permission";
 import { displayDate } from "../../utils/display";
-import StateEmpty from "../../components/StateEmpty.vue";
 import StateLoading from "../../components/StateLoading.vue";
 import StateError from "../../components/StateError.vue";
 import KpiCard from "../../components/KpiCard.vue";
@@ -444,6 +445,16 @@ onMounted(async () => {
   font-family: var(--el-font-family);
 }
 
+.table-empty {
+  min-height: 220px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  color: #8a97ab;
+  font-size: 14px;
+  font-weight: 500;
+  letter-spacing: 0.02em;
+}
 </style>
 
 <style>