Model Server.ServerRedundancy via generated subtype instances (#3981)

[marcschier]

Description

Refactors the Server.ServerRedundancy address-space modeling to materialize the correct generated subtype instance for the configured RedundancySupport mode instead of keeping a single base ServerRedundancyState, mutating its TypeDefinitionId, and adding the mode-specific children (CurrentServerId / ServerUriArray) via hand-written PropertyState construction.

Server.ServerRedundancy is now exposed as:

• TransparentRedundancyType (TransparentRedundancyState) for Transparent — with the generated CurrentServerId,
• NonTransparentRedundancyType (NonTransparentRedundancyState) for Cold/Warm/Hot/HotAndMirrored — with the generated ServerUriArray,
• the base ServerRedundancyType for None.

The mode-specific members come from the generated information model rather than hand-built PropertyState nodes, and no hardcoded numeric redundancy-type NodeIds remain (ObjectTypeIds.* are used throughout). The well-known instance NodeIds (Server_ServerRedundancy_RedundancySupport, _RedundantServerArray, _CurrentServerId, _ServerUriArray) and values are preserved when the node is promoted to the subtype.

What changed

Generic core primitive (Opc.Ua.Server)

• New AsyncCustomNodeManager.ReplacePredefinedInstanceSubtypeAsync(...), exposed via its own IPredefinedNodeSubtypeReplacer capability interface (documented in Docs/CoreNodeManagerVsCustomNodeManager2.md). It replaces a registered predefined instance node with a differently-typed instance (e.g. a generated subtype), preserving the node's identity (NodeId, BrowseName, parent), copying overlapping children's NodeIds and values by BrowseName, assigning caller-supplied well-known NodeIds to subtype-only children, swapping the address-space index, and emitting a ModelChange. It is generic and reusable beyond redundancy, and builds on the source-generator-provided typed CreateInstanceOf<Type> factories.

Server redundancy (Opc.Ua.Redundancy.Server)

• New injectable ServerRedundancyController / IServerRedundancyController with:
  • the single-source RedundancySupport → ObjectTypeIds.* mapping (GetTypeDefinitionId),
  • a real runtime ChangeModeAsync(mode) that re-materializes Server.ServerRedundancy as the new subtype in place and raises a ModelChange so connected clients observe the new type definition/members.
• ServerRedundancyStartupTask is now a thin delegate to the controller; the DI registration wires the controller and IServerRedundancyController.

Core DiagnosticsNodeManager

• Removed AddServerRedundancyStringProperty / AddServerRedundancyStringArrayProperty and the dynamic ApplyServerRedundancyTypeDefinition mutation; keeps only the generated AddRedundantServerArray optional-child helper on the base node.

Design notes

• The solution intentionally leverages the source generator (typed CreateInstanceOf<Subtype> factories, generated subtype state classes, generated AddRedundantServerArray, ObjectTypeIds/VariableIds, and the generic activator-based NodeStateFactory dispatch). It is OK to break back-compat here as the redundancy area is new in 2.0.
• The base generated Server model registers CurrentServerId/ServerUriArray as orphaned loose predefined nodes (no parent); the promotion adopts the mode's member as a typed subtype child at its well-known NodeId and drops the other mode's member.

Note: this branch is stacked on the unmerged OPCFoundation#3918 (base
odestatestorage) and also carries the sample-image containerization work for OPCFoundation#3984 (Dockerfiles + docker-image.yml matrix). Both will be split/rebased onto master once OPCFoundation#3918 lands.

Related Issues

• Fixes Model Server.ServerRedundancy via generated subtype instances (TransparentRedundancyState / NonTransparentRedundancyState) OPCFoundation/UA-.NETStandard#3981
• Follow-up to review feedback on OPC UA Part 4 6.6 Redundancy (server + client) with opt-in distributed high-availability OPCFoundation/UA-.NETStandard#3918 (stacked on that branch; base is nodestatestorage).

Testing

• Opc.Ua.Redundancy.Server.Tests: full suite green (492/492 on net10.0), including new subtype/browse-model assertions and a runtime mode-change test.
• Opc.Ua.Server.Tests: new ReplacePredefinedInstanceSubtypeAsync unit tests (identity/child-NodeId preservation, argument validation).
• Opc.Ua.InformationModel.Tests RedundancyModelTests conformance: green.
• Builds green on net10.0 and net48.

Checklist

• I have signed the CLA and read the CONTRIBUTING doc.
• I have added tests that prove my fix is effective or that my feature works and increased code coverage.
• I have added all necessary documentation.
• I have verified that my changes do not introduce (new) build or analyzer warnings.
• I ran all tests locally using the UA.slnx solution against at least .net framework and .net 10, and all passed.
• I fixed all failing and flaky tests in the CI pipelines and all CodeQL warnings.
• I have addressed all PR feedback received.