review(Commons): record findings + add deferred-sink/equip-nodeid tests, fix stale Phase7 doc

Code review at HEAD 7286d320. Commons-001 (stale Phase7 telemetry doc) fixed;
Commons-003/004 close test-coverage gaps (DeferredAddressSpaceSink/ServiceLevelPublisher
forwarding seam + EquipmentNodeIds whitespace branch). Commons-002 (CorrelationId
typing) deferred as cross-cutting.

src/Core/ZB.MOM.WW.OtOpcUa.Commons/Observability/OtOpcUaTelemetry.cs

@@ -76,7 +76,7 @@ public static class OtOpcUaTelemetry
         return activity;
     }
 
-    /// <summary>Span wrapping a full OPC UA address-space rebuild (Phase7 plan → apply).</summary>
+    /// <summary>Span wrapping a full OPC UA address-space rebuild (AddressSpace plan → apply).</summary>
     public static Activity? StartAddressSpaceRebuildSpan()
         => ActivitySource.StartActivity("otopcua.opcua.address_space_rebuild", ActivityKind.Internal);
 }