feat(adminfinance): 新增预计收入指标并优化明细查询性能

- 财务看板增加预计收入与待结算订单数统计
- 明细列表 COUNT 改为仅扫描 rental_orders 主表，避免 5-JOIN 子查询
- 统一前后端结算差异判定阈值为常量 5 分
- 修复日期选择器使用 UTC 日期导致东八区凌晨偏移前一天的问题

frontend/src/features/admin/views/AdminFinanceDetailsView.vue

@@ -2,11 +2,15 @@
 import { Search } from '@element-plus/icons-vue'
 import { onMounted, reactive, ref } from 'vue'
 
-import { fetchFinanceDetails, type FinanceDetail } from '@/features/admin/api/adminFinance'
+import {
+  fetchFinanceDetails,
+  SETTLEMENT_DIFF_THRESHOLD_CENT,
+  type FinanceDetail,
+} from '@/features/admin/api/adminFinance'
 import { adminPath } from '@/shared/utils/adminPath'
 import { formatCentWithSymbol } from '@/shared/utils/money'
 import { orderStatusLabel } from '@/shared/utils/statusLabels'
-import { formatDateTime } from '@/shared/utils/time'
+import { formatDateTime, formatInputDate } from '@/shared/utils/time'
 import AdminTablePagination from '../components/AdminTablePagination.vue'
 
 const loading = ref(false)
@@ -102,10 +106,6 @@ function defaultStartDate() {
 function defaultEndDate() {
   return formatInputDate(new Date())
 }
-
-function formatInputDate(date: Date) {
-  return date.toISOString().slice(0, 10)
-}
 </script>
 
 <template>
@@ -236,7 +236,10 @@ function formatInputDate(date: Date) {
           }}</span>
           <span
             class="amount-text amount-cell"
-            :class="{ 'amount-danger': Math.abs(row.settlement_diff_amount_cent) >= 5 }"
+            :class="{
+              'amount-danger':
+                Math.abs(row.settlement_diff_amount_cent) >= SETTLEMENT_DIFF_THRESHOLD_CENT,
+            }"
           >
             {{ moneyCent(row.settlement_diff_amount_cent) }}
           </span>