移除历史状态归一化及相关遗留逻辑

- 移除 LegacyStatusNormalizationMigrator，仅保留 AreaLayoutModeDefaultMigrator
- 删除 WmsDispatchStatus 枚举、常量和全局 using
- 统一所有 DbContext 注入为 MiGuDbContext，移除 PlatformDbContext
- 服务实体操作统一用 IEditableRepository<T>，移除本地实现
- 移除 WmsService 的 MigrateLegacyAsync 方法
- 精简接口模型，移除部分字段和请求体
- 前端保存容器时 status 字段取自已有数据，移除写死默认值
- 更新文档，去除旧说明，统一数据库初始化流程

MiGu.Server/Controllers/FleetController.cs

@@ -15,9 +15,9 @@ public sealed class FleetController : ControllerBase
     private readonly FleetHealthService _health;
     private readonly CdmTaskSyncer _cdmSyncer;
     private readonly AlarmCollector _alarmCollector;
-    private readonly PlatformDbContext _db;
+    private readonly MiGuDbContext _db;
 
-    public FleetController(FleetHealthService health, CdmTaskSyncer cdmSyncer, AlarmCollector alarmCollector, PlatformDbContext db)
+    public FleetController(FleetHealthService health, CdmTaskSyncer cdmSyncer, AlarmCollector alarmCollector, MiGuDbContext db)
     {
         _health = health;
         _cdmSyncer = cdmSyncer;