add finance cost allocation detail

finance/src/main/java/com/baiyue/finance/controller/PlatformFinanceController.java

@@ -162,6 +162,12 @@ public class PlatformFinanceController {
         return FinanceResponses.success(queryService.payableSettlements(customerId));
     }
 
+    @GetMapping("/cost-entries/{costId}")
+    @PreAuthorize("hasAuthority('platform:finance:cost:view')")
+    public ApiResponse<?> cost(@PathVariable long costId, @RequestParam long customerId) {
+        return FinanceResponses.success(queryService.cost(customerId, costId));
+    }
+
     @PostMapping("/cost-entries")
     @PreAuthorize("hasAuthority('platform:finance:cost:create')")
     @BusinessAudit(event = "FINANCE_COST_CREATE", resourceType = "FINANCE_COST")

finance/src/main/java/com/baiyue/finance/dto/FinanceReadModels.java

@@ -102,6 +102,19 @@ public final class FinanceReadModels {
         LocalDateTime createdAt,
         int version) {}
 
+    public record CostDetail(PayableSettlement cost, List<CostAllocation> allocations) {}
+
+    public record CostAllocation(
+        long id,
+        long costId,
+        long orderId,
+        Long inboundId,
+        BigDecimal volumeCbm,
+        BigDecimal totalVolumeCbm,
+        BigDecimal allocationRate,
+        BigDecimal allocatedAmount,
+        boolean roundingAdjustment) {}
+
     /** Client-safe receipt view. Voucher and operator/internal fields are deliberately absent. */
     public record ClientReceipt(
         long id,

finance/src/main/java/com/baiyue/finance/service/FinanceQueryService.java

@@ -7,6 +7,8 @@ import com.baiyue.finance.dto.FinanceReadModels.ClientReceipt;
 import com.baiyue.finance.dto.FinanceReadModels.ClientReceiptAllocation;
 import com.baiyue.finance.dto.FinanceReadModels.BillRevision;
 import com.baiyue.finance.dto.FinanceReadModels.CustomerAccount;
+import com.baiyue.finance.dto.FinanceReadModels.CostAllocation;
+import com.baiyue.finance.dto.FinanceReadModels.CostDetail;
 import com.baiyue.finance.dto.FinanceReadModels.FeePoolItem;
 import com.baiyue.finance.dto.FinanceReadModels.PayableSettlement;
 import com.baiyue.finance.dto.FinanceReadModels.PlatformReceipt;
@@ -143,6 +145,19 @@ public class FinanceQueryService {
             }, customerId);
     }
 
+    public CostDetail cost(long customerId, long costId) {
+        PayableSettlement cost = payableSettlements(customerId).stream()
+            .filter(item -> item.id() == costId).findFirst()
+            .orElseThrow(() -> new BizException(ResultCode.NOT_FOUND, "成本不存在或不属于客户"));
+        List<CostAllocation> allocations = jdbc.query(
+            "SELECT id,cost_id,order_id,inbound_id,volume_cbm,total_volume_cbm,allocation_rate,allocated_amount,rounding_adjustment FROM fin_cost_allocation WHERE tenant_id=? AND cost_id=? ORDER BY id",
+            (rs, rowNum) -> new CostAllocation(rs.getLong("id"), rs.getLong("cost_id"), rs.getLong("order_id"),
+                nullableLong(rs, "inbound_id"), rs.getBigDecimal("volume_cbm"), rs.getBigDecimal("total_volume_cbm"),
+                rs.getBigDecimal("allocation_rate"), rs.getBigDecimal("allocated_amount"), rs.getBoolean("rounding_adjustment")),
+            customerId, costId);
+        return new CostDetail(cost, allocations);
+    }
+
     public List<ClientReceipt> clientReceipts(long customerId) {
         requireCustomer(customerId);
         return jdbc.query("SELECT id,receipt_no,received_amount,received_at,payment_method,currency_code,status FROM fin_receipt WHERE tenant_id=? AND status='CONFIRMED' ORDER BY received_at DESC,id DESC",