Files
Adds an opt-in pass-3 walk of the upstream TypesFolder (i=86) so the OPC UA Client driver can mirror upstream type definitions into the local address space. Honours the curation rules from PR-7 (#359). Structural mirror only — binary-encoding priming via LoadDataTypeSystem is tracked as a follow-up because that helper was removed from the public ISession surface in OPCFoundation.NetStandard 1.5.378+. - IAddressSpaceBuilder.RegisterTypeNode (default no-op for back-compat) - MirroredTypeNodeInfo + MirroredTypeKind in Core.Abstractions - OpcUaClientDriverOptions.MirrorTypeDefinitions (default false) - DiscoverAsync pass-3: FetchTypeTreeAsync + recursive HasSubtype walk per branch (ObjectTypes/VariableTypes/DataTypes/ReferenceTypes), best-effort IsAbstract read, IncludePaths/ExcludePaths still applied - 6 new unit tests; all 153 OpcUaClient unit tests pass Closes #280