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is deleted rather than fixed, and #507 closes as superseded by /raw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.

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Drivers/DarkAddressSpaceReasons.cs

@@ -18,17 +18,11 @@ internal static class DarkAddressSpaceReasons
         "empty equipment-tag plan set this batch, so this parity has nothing to compare. Raw-tag parse " +
         "intent is covered by TagConfigCorpusParityTests (RawTagEntry round-trip) + TagConfigIntentTests.";
 
-    /// <summary>Discovered-node INJECTION is dormant in v3 (Wave-B review M1). The v2 path grafted a driver's
-    /// FixedTree under an equipment folder (equipment bound a driver); v3 retired that binding and discovered
-    /// raw tags are authored explicitly via the Batch-2 <c>/raw</c> browse-commit flow. <c>HandleDiscoveredNodes</c>
-    /// hard-short-circuits, so these v2 injection scenarios have no live path to assert; re-migrating injection
-    /// onto the raw device subtree is a separate follow-up. The dormant guard itself is pinned by
-    /// <c>DriverHostActorDiscoveryTests.Discovered_nodes_are_ignored_dormant_in_v3</c>.</summary>
-    public const string DiscoveryInjectionDormantV3 =
-        "v3: discovered-node injection is DORMANT (Wave-B review M1) — equipment no longer binds a driver, so the " +
-        "v2 FixedTree-under-equipment graft has no live path. Discovered raw tags are authored via the /raw " +
-        "browse-commit flow. HandleDiscoveredNodes short-circuits (pinned by Discovered_nodes_are_ignored_dormant_in_v3); " +
-        "re-migrating injection onto the raw device subtree is a separate follow-up.";
+    // DiscoveryInjectionDormantV3 was removed with the injection path itself (§8.2, Gitea #507). The 18
+    // tests it skipped were v2 characterization tests — they asserted an equipment-rooted graft
+    // (EquipmentRootNodeId == "EQ-1") that v3 cannot produce, so they were deleted rather than unskipped.
+    // Discovered raw tags are authored through the /raw browse-commit flow; IRediscoverable now surfaces a
+    // re-browse prompt instead (DriverInstanceActorRediscoverySignalTests).
 
     /// <summary>Equipment↔device host binding is architecturally retired in v3.</summary>
     public const string EquipmentDeviceBindingRetired =