test(v3): migrate OpcUaServer.Tests + Host.IntegrationTests to v3 dark address space

Migrate the server composer/applier + 2-node harness tests off the retired
Namespace/NamespaceKind + equipment→driver/device binding schema onto the v3
greenfield shape (raw-only Tag; DriverInstance-RawFolderId; equipment via UnsLine).

OpcUaServer.Tests (134 build errors -> green, 335 pass / 4 skip):
- LIVE (migrated, passing): VirtualTag-historize + ScriptedAlarm composition,
  composer purity/hierarchy, applier MaterialiseHierarchy + MaterialiseEquipmentTags
  idempotency (hand-fed applier, not dark).
- SKIP dark-until-Batch-4: {{equip}} token expansion, applier equipment-namespace
  E2E (equipment-tag variable materialization).
- RETIRE-with-comment / skip: alias-tag (Tag.EquipmentId binding gone) + device-host
  equipment binding (architecturally removed).
- Add local DarkAddressSpaceReasons Skip-reason constants (mirrors Runtime.Tests).

Host.IntegrationTests (green, in-memory): drop deleted-Namespace seeds from
MultiClusterScoping + DriverReconnect; reshape EquipmentNamespaceMaterialization to
assert the DARK contract (folder nodes decode, EquipmentTags empty despite a seeded
v3 raw tag) with the full raw-tag->EquipmentTag materialization kept as a
Batch-4-pending Skip.

Tests-only; no src/ changes.

tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/AddressSpaceComposerPurityTests.cs

@@ -136,7 +136,6 @@ public sealed class AddressSpaceComposerPurityTests
         var result = AddressSpaceComposer.Compose(
             Array.Empty<UnsArea>(), Array.Empty<UnsLine>(), Array.Empty<Equipment>(),
             Array.Empty<DriverInstance>(), Array.Empty<ScriptedAlarm>(),
-            Array.Empty<Tag>(), Array.Empty<Namespace>(),
             virtualTags: new[] { vt },
             scripts: new[] { script });
 
@@ -174,7 +173,6 @@ public sealed class AddressSpaceComposerPurityTests
         var result = AddressSpaceComposer.Compose(
             Array.Empty<UnsArea>(), Array.Empty<UnsLine>(), Array.Empty<Equipment>(),
             Array.Empty<DriverInstance>(), Array.Empty<ScriptedAlarm>(),
-            Array.Empty<Tag>(), Array.Empty<Namespace>(),
             virtualTags: new[] { vt },
             scripts: new[] { script });
 
@@ -200,7 +198,6 @@ public sealed class AddressSpaceComposerPurityTests
         var result = AddressSpaceComposer.Compose(
             Array.Empty<UnsArea>(), Array.Empty<UnsLine>(), Array.Empty<Equipment>(),
             Array.Empty<DriverInstance>(), Array.Empty<ScriptedAlarm>(),
-            Array.Empty<Tag>(), Array.Empty<Namespace>(),
             virtualTags: new[] { vt },
             scripts: Array.Empty<Script>());
 
@@ -213,7 +210,6 @@ public sealed class AddressSpaceComposerPurityTests
     private static Equipment NewEquipment(string id) => new()
     {
         EquipmentId = id,
-        DriverInstanceId = "drv-1",
         UnsLineId = "line-1",
         Name = id,
         MachineCode = id.ToUpperInvariant(),
@@ -223,7 +219,6 @@ public sealed class AddressSpaceComposerPurityTests
     {
         DriverInstanceId = id,
         ClusterId = "cluster-1",
-        NamespaceId = "ns-1",
         Name = id,
         DriverType = "Stub",
         DriverConfig = "{\"k\":\"v\"}",