fix(lastleg): preserve warehouse pallet business conflict responses

lastleg-service/src/main/java/com/baiyue/lastleg/inboundplan/pda/gateway/HttpWarehouseResourceGateway.java

@@ -179,15 +179,14 @@ public class HttpWarehouseResourceGateway implements WarehouseResourceGateway {
             .header("X-Internal-Service-Token", internalToken).retrieve()
             .onStatus(HttpStatusCode::isError, (request, result) -> { throw palletLookupFailure(result.getStatusCode()); })
             .body(WarehousePalletResponse.class);
-        if (response == null || response.data() == null) throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE,
-            "Warehouse pallet service returned no usable response");
+        requirePalletResponse(response);
         return new WarehousePalletReference(response.data().id(), response.data().palletCode(), response.data().warehouseId(),
             response.data().locationId(), response.data().status(), response.data().fbaWarehouseCode(),
             response.data().unitPrice(), response.data().version());
     }
 
     private ResponseStatusException palletLookupFailure(HttpStatusCode status) {
-        return new ResponseStatusException(status.value() == 404 ? HttpStatus.NOT_FOUND
+        return new ResponseStatusException(status.value() == 409 ? HttpStatus.CONFLICT : status.value() == 404 ? HttpStatus.NOT_FOUND
             : (status.is4xxClientError() ? HttpStatus.BAD_REQUEST : HttpStatus.SERVICE_UNAVAILABLE),
             status.value() == 404 ? "Warehouse pallet was not found" : "Warehouse pallet lookup failed");
     }
@@ -199,14 +198,23 @@ public class HttpWarehouseResourceGateway implements WarehouseResourceGateway {
             .retrieve().onStatus(HttpStatusCode::isError, (request, result) -> {
                 throw palletLookupFailure(result.getStatusCode());
             }).body(WarehousePalletResponse.class);
+        requirePalletResponse(response);
+        return response;
+    }
+
+    /** 托盘状态冲突是业务拒绝，不能把HTTP 200内的A0409误报为仓储服务不可用。 */
+    private void requirePalletResponse(WarehousePalletResponse response) {
+        if (response != null && "A0409".equals(response.code())) {
+            throw new ResponseStatusException(HttpStatus.CONFLICT,
+                response.message() == null || response.message().isBlank() ? "Warehouse pallet state conflicts with this operation" : response.message());
+        }
         if (response != null && "A0404".equals(response.code())) {
             throw new ResponseStatusException(HttpStatus.NOT_FOUND, "Warehouse pallet was not found");
         }
-        if (response == null || response.data() == null) {
+        if (response == null || !"200".equals(response.code()) || response.data() == null) {
             throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE,
                 "Warehouse pallet service returned no usable response");
         }
-        return response;
     }
 
     private WarehousePalletReference reference(WarehousePalletData pallet) {