Files
Adds the 9th capability interface (IMethodInvoker) so the OPC UA Client driver can mirror upstream OPC UA Method nodes into the local address space and forward Call invocations as Session.CallAsync. Method-bearing servers (e.g. ProgramStateMachine, Acknowledge / Confirm methods, custom control surfaces) now show up downstream instead of being silently filtered out. - Core.Abstractions: IMethodInvoker + MethodCallResult; default no-op IAddressSpaceBuilder.RegisterMethodNode + MirroredMethodNodeInfo + MethodArgumentInfo. Default impls keep tag-based drivers and existing builders compiling without forced overrides. - OpcUaClientDriver: BrowseRecursiveAsync now lifts the Method node-class filter; for each method it walks HasProperty to pick up InputArguments + OutputArguments and decodes the Argument extension objects into MethodArgumentInfo. Status-codes pass through verbatim (cascading quality), local NodeId-parse + lost-session faults surface as BadNodeIdInvalid / BadCommunicationError. - 7 new unit tests cover the capability surface, the DTO shapes, and the back-compat default no-op for RegisterMethodNode. Suite green at 160/160. Server-side OnCallMethod dispatch (wiring local MethodNode handlers to IMethodInvoker.CallMethodAsync inside DriverNodeManager) is deferred to a follow-up — the driver-side surface + browse mirror ship cleanly here. Closes #281 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>