Phase 1a of the v2 entity-model rewrite. Adds:
public byte[] RowVersion { get; set; } = Array.Empty<byte>();
and the EF Core mapping
e.Property(x => x.RowVersion).IsRowVersion();
to 12 live-edit entities:
Equipment, DriverInstance, Device, Tag, PollGroup, Namespace,
UnsArea, UnsLine, NodeAcl, Script, VirtualTag, ScriptedAlarm
These are the entities that v2 admins will edit directly via
AdminOperationsActor (no draft staging). RowVersion enables
last-write-wins detection when two operators race on the same row.
GenerationId FKs are still in place on these entities (removed in Task 14b);
this commit only adds the rowversion column so the migration in Task 14f can
emit ADD COLUMN before DROP FK as a single atomic step.
4bb4ad8acb