refactor(drivers): delete the dead discovered-node injection path (§8.2, #507)

#507 was filed as "injection inert in v3, re-migrate onto the raw subtree".
Reading it, the retained code is not revivable: it resolves equipment from
EquipmentNode.DriverInstanceId UNION EquipmentTags, and BOTH are structurally
empty in v3 (AddressSpaceComposer always constructs EquipmentNode with a null
DriverInstanceId; DeploymentArtifact hard-codes an empty EquipmentTags set).
Removing the guard would have changed a log line and injected nothing. So it
is deleted rather than fixed, and #507 closes as superseded by /raw
browse-commit.

Removed: HandleDiscoveredNodes, PartitionDiscoveredByDeviceHost,
ShouldWarnPartition, PlansRoutingEqual, ApplyDiscoveredPlansForDriver,
_discoveredByDriver, the redeploy re-inject tail, DiscoveredNodeMapper,
DiscoveredInjection, AddressSpaceApplier.MaterialiseDiscoveredNodes,
OpcUaPublishActor.MaterialiseDiscoveredNodes, and the Runtime-local copies of
CapturingAddressSpaceBuilder/DiscoveredNode.

The connect-time discovery loop goes too (StartDiscovery, RediscoverTick,
HandleRediscoverAsync, DiscoveredNodesReady, TriggerRediscovery). With
injection gone it had no consumer, and leaving it would either dead-letter or
keep browsing real devices up to ~15x per connect to drop the result.
ITagDiscovery itself stays — the /raw browse picker drives it through
Commons/Browsing/DiscoveryDriverBrowser, which never went through the actor,
so the picker is unaffected.

deferment.md §4.4 called the 18 DiscoveryInjectionDormantV3 tests "Real —
blocked on #507". They are not: they assert an equipment-rooted graft
(EquipmentRootNodeId == "EQ-1") that v3 cannot produce, so they could never
have unskipped as written. Deleted along with DiscoveredNodeMapperTests, the
CapturingAddressSpaceBuilder tests, and the MaterialiseDiscoveredNodes tests
in AddressSpaceApplierTests/OpcUaPublishActorTests. Runtime.Tests skipped:
31 -> 13.

IHostConnectivityProbe is deliberately NOT resolved here. GetHostStatuses()
has no production call site and nothing writes a DriverHostStatus row, but the
table was re-created in the v3 initial migration, so deleting on inference
would be wrong. Split to Gitea #521 with both options costed.

CLAUDE.md, docs/drivers/{Galaxy,TwinCAT,MTConnect}.md updated — they described
the seam as dead.

Build clean; Runtime.Tests 476 passed / 13 skipped; OpcUaServer.Tests 362
passed / 4 skipped.

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/OpcUa/OpcUaPublishActor.cs

@@ -85,15 +85,6 @@ public sealed class OpcUaPublishActor : ReceiveActor, IWithTimers
     public sealed record RebuildAddressSpace(
         CorrelationId Correlation, DeploymentId? DeploymentId = null, byte[]? Artifact = null);
 
-    /// <summary>Inject driver-discovered nodes (FixedTree) under an equipment at runtime (post-connect).</summary>
-    /// <param name="EquipmentRootNodeId">The OPC UA NodeId of the equipment root folder to inject the
-    /// discovered nodes under (e.g. "EQ-3686c0272279"); also the node the NodeAdded model-change is
-    /// announced under.</param>
-    public sealed record MaterialiseDiscoveredNodes(
-        string EquipmentRootNodeId,
-        IReadOnlyList<DiscoveredFolder> Folders,
-        IReadOnlyList<DiscoveredVariable> Variables);
-
     public sealed record ServiceLevelChanged(byte ServiceLevel);
 
     private readonly IOpcUaAddressSpaceSink _sink;
@@ -284,7 +275,6 @@ public sealed class OpcUaPublishActor : ReceiveActor, IWithTimers
         Receive<AlarmStateUpdate>(HandleAlarmUpdate);
         Receive<AlarmQualityUpdate>(HandleAlarmQualityUpdate);
         Receive<RebuildAddressSpace>(HandleRebuild);
-        Receive<MaterialiseDiscoveredNodes>(HandleMaterialiseDiscovered);
         Receive<ServiceLevelChanged>(HandleServiceLevelChanged);
         Receive<RedundancyStateChanged>(HandleRedundancyStateChanged);
         Receive<DbHealthProbeActor.DbHealthStatus>(HandleDbHealthStatus);
@@ -539,28 +529,6 @@ public sealed class OpcUaPublishActor : ReceiveActor, IWithTimers
         }
     }
 
-    /// <summary>Forwards driver-discovered (FixedTree) nodes to the applier so they are injected under
-    /// the equipment at runtime. No-op (logged) when no applier is wired (dev/Mac/legacy seam), matching the
-    /// optional-applier tolerance of <see cref="HandleRebuild"/>.</summary>
-    private void HandleMaterialiseDiscovered(MaterialiseDiscoveredNodes msg)
-    {
-        if (_applier is null)
-        {
-            _log.Debug("OpcUaPublish: no applier wired — discarding MaterialiseDiscoveredNodes for {Equipment}", msg.EquipmentRootNodeId);
-            return;
-        }
-        var failedNodes = _applier.MaterialiseDiscoveredNodes(msg.EquipmentRootNodeId, msg.Folders, msg.Variables);
-        if (failedNodes > 0)
-        {
-            // archreview 01/S-1: a swallowed discovered-node injection failure surfaces at Error + the
-            // dedicated meter instead of vanishing into per-node Warnings.
-            OtOpcUaTelemetry.OpcUaApplyFailed.Add(1, new KeyValuePair<string, object?>("kind", "nodes"));
-            _log.Error(
-                "OpcUaPublish: discovered-node injection DEGRADED for {Equipment} (failedNodes={FailedNodes}) — some discovered nodes may be missing",
-                msg.EquipmentRootNodeId, failedNodes);
-        }
-    }
-
     private void HandleServiceLevelChanged(ServiceLevelChanged msg)
     {
         // Always publish the FIRST computed level, even if it equals the byte-default 0. Otherwise a