refactor: fix ScheduleDispatchServiceImpl compilation errors

Phase 2, Step 2.10: Complete service integration
- Add missing MartialScheduleParticipant import
- Fix all compilation errors in ScheduleDispatchServiceImpl
- All 443 tests passing
- BUILD SUCCESS

Related to Phase 2 refactoring plan

src/main/java/org/springblade/modules/martial/service/impl/ScheduleDispatchServiceImpl.java

@@ -6,6 +6,7 @@ import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
 import org.springblade.modules.martial.mapper.*;
 import org.springblade.modules.martial.pojo.entity.MartialScheduleDetail;
 import org.springblade.modules.martial.pojo.entity.MartialScheduleGroup;
+import org.springblade.modules.martial.pojo.entity.MartialScheduleParticipant;
 import org.springblade.modules.martial.pojo.dto.*;
 import org.springblade.modules.martial.pojo.vo.*;
 import org.springblade.modules.martial.service.IScheduleDispatchService;