* Refactor MonitoredItem.ValueChanged & cert validation
Refactored MonitoredItem.ValueChanged for correctness, performance, and comprehensive test coverage, including improved deadband and array handling. Rewrote equality logic for Variants and arrays. Made certificate validation thread-safe using ConcurrentDictionary and proper semaphore usage. Added extensive unit tests and benchmarks for value change detection.
* Implement DiagnosticsNodeManager using AsyncCustomNodeManager
* Implement CoreNodeManager using AsyncCustomNodeManager
* Use Interfaces Introduced with 1.5.378
Refactor to use interfaces for node managers and server
Replaced concrete types with interfaces (e.g., IMasterNodeManager, ICoreNodeManager, IDiagnosticsNodeManager, IConfigurationNodeManager, IServerBase) across method signatures, properties, and internal structures to improve abstraction and flexibility.
* Refactor CoreNodeManager to be Based on CustomNodeManager2
* Add Test
* fix
This pull request modernizes the OPC UA .NET codebase and tests, removes .NET Standard 2.0 support from certificate/security code, and updates test code to use C# 12 and .NET 8+ features for clarity and maintainability.
- Certificate and BouncyCastle interop files (e.g., CertificateBuilder.cs, X509Extensions.cs, X509SignatureFactory.cs) are refactored to drop NETSTANDARD2_0 support and use modern .NET APIs and conditional compilation.
- Test code across the codebase is updated to use default, strongly-typed Parse methods, collection expressions, and improved async/await patterns.
- Exception handling and assertions in tests are modernized, and test method naming is made consistent with Async suffixes.
- The project and build files are updated to clarify Roslynator analyzer usage and remove obsolete netstandard tags.
- General code and test cleanup includes improved null safety, type safety, and removal of deprecated or unused code.