# Description
The CTT/compliance `ReferenceNodeManager` built its ~6,000 node address
space entirely in imperative C#. This PR migrates it to a
source-generated `[NodeManager]` partial driven by an exported NodeSet2
model (`ReferenceServer.NodeSet2.xml`), mirroring the
`MinimalBoilerServer` sample and completing the goal of issue #4204.
The address space is now materialized from the model by the source
generator. The large orchestration body was kept but converted from
create-based to **find-instead-of-create**: each `Create*` primitive now
looks up the model-materialized node via `FindPredefinedNode<T>` and
re-applies runtime values, DataAccess metadata, and write handlers,
rather than constructing nodes from scratch. This keeps the
deterministic value seeding and behavior wiring intact while the
structure comes from the model.
## Notable details for reviewers
- **Idempotent reference wiring.** The mesh references in the
`References` folder are already present in the model, so the historic
manual `AddReference` calls would throw on duplicates. Added a small
`AddReferenceIfMissing` helper so those calls are safe.
- **Non-string NodeIds.** The `NodeIds` folder assigns numeric / GUID /
opaque NodeIds. The model exports those nodes with their final ids, so
find-by-string-path no longer works; added `CreateVariableById(NodeId)`
to locate them by their real id.
- **Generator bug fix (worth a careful look).**
`ModelDesignExtensions.GetValueRankAsCode` reconstructed `ValueRank` as
`dimensions.Length + 1`, so a node with `ArrayDimensions="3,3"` was
emitted as `ValueRank = 3`. This affected **any** NodeSet2 with a fixed
multi-dimensional array (rank-3 matrices, `BadTypeMismatch` on
whole-matrix writes, wrong decoded dimensions). Corrected to
`dimensions.Length` and updated the unit tests that had codified the
off-by-one.
## Validation
- `ReferenceServerTest`: 44/44 on net10.0 and net48
- `Opc.Ua.SourceGeneration.Core.Tests`: pass on
net8.0/net9.0/net10.0/net48
- Integration on net10.0: ComplexTypes, Client, History, Sessions,
Subscriptions all pass
- Clean build, no new analyzer warnings
## Related Issues
- Fixes#4204
## Checklist
_Put an `x` in the boxes that apply. You can complete these step by step
after opening the PR._
- [ ] I have signed the
[CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf)
and read the
[CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md)
doc.
- [x] 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.
- [x] I have verified that my changes do not introduce (new) build or
analyzer warnings.
- [x] 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.
---------
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
romanett