80 feature implement derived property textualnotation

CLAUDE.md

@@ -35,6 +35,7 @@ Test framework: **NUnit**. Test classes use `[TestFixture]` and `[Test]` attribu
 
 - favour duplicated code in codegeneration to have staticaly defined methods that provide performance over reflection based code.
 - code generation is done by processing the UML model and creating handlebars templates
+- **When working on the grammar/textual notation code generator** (`SysML2.NET.CodeGenerator/HandleBarHelpers/RulesHelper.cs` and related grammar processing): read `SysML2.NET.CodeGenerator/GRAMMAR.md` for the KEBNF grammar model, cursor/builder conventions, and code-gen patterns already handled.
 
 ### Code Generation Pipeline
 
@@ -118,3 +119,4 @@ Auto-generated DTOs use structured namespaces reflecting the KerML/SysML package
 - Prefer switch expressions/statements over if-else chains when applicable
 - Prefer indexer syntax (e.g., 'list[^1]') and range syntax (e.g., 'array[1..^1]') over LINQ methods (e.g., 'list.Last()', 'list.Skip(1).Take(n)') when applicable
 - Use meaningful variable names instead of single-letter names in any context (e.g., 'charIndex' instead of 'i', 'currentChar' instead of 'c', 'element' instead of 'e')
+- Use 'NotSupportedException' (not 'NotImplementedException') for placeholder/stub methods that require manual implementation