feat(wm-revenue): #53 水表全生命周期管理
- Entity: WaterMeter, MeterInstallRecord, MeterReplaceRecord, MeterLifecycleLog
- Enum: MeterStatus (IN_STOCK/INSTALLED/DISMANTLED/SCRAPPED/REPAIRING)
- Mapper: WaterMeterMapper, MeterInstallRecordMapper, MeterReplaceRecordMapper, MeterLifecycleLogMapper
- Service: MeterLifecycleService (入库/安装/查询), MeterReplaceService (换表/报废/审批), MeterStatsService (统计)
- Controller: MeterController (/api/revenue/meter/*), MeterReplaceController (/api/revenue/meter-replace/*), MeterStatsController (/api/revenue/meter-stats/*)
- DDL: V_meter_lifecycle.sql (4张表 + 索引)
- Test: MeterLifecycleTest (12个测试用例)
