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

backend/internal/modules/adminfinance/dto.go

@@ -34,10 +34,12 @@ type FinanceSummaryDTO struct {
 	OwnerShouldIncomeAmountCent int64 `json:"owner_should_income_amount_cent"`
 	OwnerWalletIncomeAmountCent int64 `json:"owner_wallet_income_amount_cent"`
 	SettlementDiffAmountCent    int64 `json:"settlement_diff_amount_cent"`
+	EstimatedIncomeAmountCent   int64 `json:"estimated_income_amount_cent"`
 	SuccessfulPayCount          int64 `json:"successful_pay_count"`
 	SuccessfulRefundCount       int64 `json:"successful_refund_count"`
 	PendingRefundCount          int64 `json:"pending_refund_count"`
 	SettledOrderCount           int64 `json:"settled_order_count"`
+	PendingSettleOrderCount     int64 `json:"pending_settle_order_count"`
 	FinancialExceptionCount     int64 `json:"financial_exception_count"`
 }
 
@@ -51,6 +53,7 @@ type FinanceDailyDTO struct {
 	OwnerShouldIncomeAmountCent int64  `json:"owner_should_income_amount_cent"`
 	OwnerWalletIncomeAmountCent int64  `json:"owner_wallet_income_amount_cent"`
 	SettlementDiffAmountCent    int64  `json:"settlement_diff_amount_cent"`
+	EstimatedIncomeAmountCent   int64  `json:"estimated_income_amount_cent"`
 	SuccessfulPayCount          int64  `json:"successful_pay_count"`
 	SuccessfulRefundCount       int64  `json:"successful_refund_count"`
 	PendingRefundCount          int64  `json:"pending_refund_count"`