Route derived public fields through unified bytecode

[rogeralsing]

Summary

• admit simple derived constructors with public instance fields into production unified bytecode
• push the existing pending class-field initializer before VM execution and consume it after the VM super construct boundary initializes this
• update constructor coverage and the decline contract to leave only derived private-field branding in this gate

Verification

• rtk dotnet test tests/Asynkron.JsEngine.Tests -c Release --filter "FullyQualifiedNameUnifiedBytecodeProductionConstructCallTests.DerivedConstructorWithInstanceField_UsesProductionFastPathAndInitializesAfterSuper|FullyQualifiedNameUnifiedBytecodeProductionConstructCallTests.SuperConstruct_InitializesThis|FullyQualifiedNameUnifiedBytecodeProductionConstructCallTests.SuperConstruct_DoubleCallThrows|FullyQualifiedNameExpressionProgramCoverageMapTests.UnifiedBytecodeExpansionContract_ListsRequiredHeadingsAndCurrentEnums"
• rtk dotnet test tests/Asynkron.JsEngine.Tests -c Release --filter "FullyQualifiedNameUnifiedBytecodeProductionConstructCallTests|FullyQualifiedNameExpressionProgramCoverageMapTests.UnifiedBytecodeExpansionContract_ListsRequiredHeadingsAndCurrentEnums"
• rtk dotnet test tests/Asynkron.JsEngine.Tests -c Release --filter "FullyQualifiedNameUnifiedBytecodeProductionEligibilityTests|FullyQualifiedNameUnifiedBytecodeProductionInvocationTests|FullyQualifiedNameUnifiedBytecodeProductionConstructCallTests|FullyQualifiedNameExpressionProgramCoverageMapTests"
• rtk dotnet build src/Asynkron.JsEngine/Asynkron.JsEngine.csproj -c Release
• rtk rg "EvaluateExpression(|ProfileEvaluateExpression(" src/Asynkron.JsEngine/Ast/TypedAstEvaluator.ExecutionPlanRunner* (no matches)
• rtk git diff --check

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.