* Add source-generated NodeManagers and fluent wiring API
Adds a fluent INodeManagerBuilder API for wiring per-node callbacks and a model-aware source generator that emits a partial CustomNodeManager2 plus an INodeManagerFactory for each design file.
Opt-in is per class via [Opc.Ua.Server.Fluent.NodeManager] on a partial class (recommended) or project-wide via the ModelSourceGeneratorGenerateNodeManager MSBuild property (legacy). The attribute supports NamespaceUri / Design selectors for multi-design projects and a GenerateFactory toggle. Diagnostics MODELGEN010 / MODELGEN011 surface unmatched bindings and non-partial classes.
Adds the ConsoleBoilerServer NativeAOT sample driving the new pipeline end-to-end with Microsoft.Extensions.Logging.Console and updated docs in Docs/SourceGeneratedNodeManagers.md.
* Add BoilerServer AOT smoke test
Verifies the source-generated Boiler.BoilerNodeManagerFactory loads
the boiler address space, registers its namespace, and dispatches the
fluent OnRead callbacks wired in BoilerNodeManager.Configure.cs.
All 3 new tests pass in JIT mode and against the NativeAOT-published
binary; total Aot.Tests suite: 71/71 pass.