Phase 536: lasso screenshot route and Cookbook proof boundary

[ExplodingUFO]

Summary

• Add a bounded Cookbook route and full-window shell state for lasso screenshot proof.
• Capture active NodeCanvasSelectionMode.Lasso transient feedback metadata before release.
• Update EN/ZH parity docs and focused tests for Phase 536 boundaries.

Test Plan

• dotnet build tests\AsterGraph.Demo.Tests\AsterGraph.Demo.Tests.csproj --verbosity minimal
• dotnet test tests\AsterGraph.Demo.Tests\AsterGraph.Demo.Tests.csproj --filter "FullyQualifiedNameDemoCookbookScreenshotGateTests|FullyQualifiedNameReactFlowParityRoadmapDocsTests|FullyQualifiedNamePostPhase506VisualQueueDocsTests|FullyQualifiedNameShellVisualCoveragePlanningDocsTests|FullyQualifiedName~DemoCookbookDocsTests" --no-build --verbosity minimal
• dotnet restore AsterGraph.sln --verbosity minimal
• dotnet build AsterGraph.sln -c Release --no-restore --verbosity minimal
• dotnet test tests\AsterGraph.Demo.Tests\AsterGraph.Demo.Tests.csproj -c Release --no-build --verbosity minimal
• git diff --check

Closes #195