Route private field-in through unified bytecode

[rogeralsing]

Summary

• allow production unified bytecode routing for class methods with private-name scopes when the body is otherwise eligible
• thread active/captured private-name scopes into the unified bytecode VM invocation bridge
• add invocation coverage for #name in receiver routing and private member read decline, then update the decline ledger/docs

Verification

• rtk dotnet test tests/Asynkron.JsEngine.Tests -c Release --filter "FullyQualifiedNameUnifiedBytecodeProductionInvocationTests.PrivateFieldIn_UsesUnifiedBytecodeProductionFastPathAndChecksBrand|FullyQualifiedNameUnifiedBytecodeProductionInvocationTests.PrivateNamedPropertyRead_StillDeclinesProductionUnifiedBytecode|FullyQualifiedNameUnifiedBytecodeProductionEligibilityTests.Evaluate_PrivateFieldIn_AcceptsAndVmChecksPrivateBrand|FullyQualifiedNameUnifiedBytecodeProductionEligibilityTests.Evaluate_PrivateNamedPropertyAccess_DeclinesWithExplicitCode|FullyQualifiedName~ExpressionProgramCoverageMapTests.UnifiedBytecodeExpansionContract_ListsRequiredHeadingsAndCurrentEnums"
• rtk dotnet test tests/Asynkron.JsEngine.Tests -c Release --filter "FullyQualifiedNameUnifiedBytecodeProductionEligibilityTests|FullyQualifiedNameUnifiedBytecodeProductionInvocationTests|FullyQualifiedName~ExpressionProgramCoverageMapTests"
• rtk dotnet build src/Asynkron.JsEngine/Asynkron.JsEngine.csproj -c Release
• rtk rg "EvaluateExpression(|ProfileEvaluateExpression(" src/Asynkron.JsEngine/Ast/TypedAstEvaluator.ExecutionPlanRunner*
• 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.