fix(wm-dispatch): #12 修复Entity-DDL-Service不一致问题，添加单元测试
修复内容:
1. DDL表名与@TableName注解对齐: dispatch_command→disp_dispatch_command, dispatch_duty_schedule→disp_duty_schedule
2. DDL列名与Entity字段camelCase映射对齐: cmd_no→command_no, type→command_type, status INT→status VARCHAR
3. Service方法与Entity字段名对齐: setCmdNo→setCommandNo, setType→setCommandType, setStatus(int)→setStatus(String)
4. 指令状态改用String枚举(ISSUED/RECEIVED/EXECUTING/COMPLETED/REJECTED)替代int
5. 新增3个单元测试: DispatchCommandTest, DutyScheduleTest, DispatchBizServiceLogicTest
6. Controller添加完整Swagger注解和DISP/SCH编号映射
7. Service增加值班交接班、指令全生命周期状态流转方法
已覆盖需求: DISP-01~05, SCH-01~02
