fix(printer):修复打印机选择逻辑并优化查询

- 调整打印机选择逻辑，确保正确获取打印机ID
- 优化SourceMapper查询，按创建时间倒序并限制结果数量- 修复可能因逻辑错误导致的打印机选择异常问题

src/main/java/com/ycwl/basic/service/printer/impl/PrinterServiceImpl.java

@@ -490,12 +490,10 @@ public class PrinterServiceImpl implements PrinterService {
             List<PrinterResp> printerList = printerMapper.listByScenicId(scenicId);
             if (printerList.size() != 1) {
                 throw new BaseException("请选择打印机");
-            } else {
-                printerId = printerList.getFirst().getId();
             }
-        } else {
-            printer = printerMapper.getById(printerId);
+            printerId = printerList.getFirst().getId();
         }
+        printer = printerMapper.getById(printerId);
         if (printer == null) {
             throw new BaseException("打印机不存在");
         }

src/main/resources/mapper/SourceMapper.xml

@@ -358,5 +358,7 @@
         select *
         from source
         where face_sample_id = #{faceSampleId} and type = #{type}
+        order by create_time desc
+        limit 1
     </select>
 </mapper>