Analyze synchronous PowerShell command regions

[Aaronontheweb]

Summary

• promote Measure-Command -Expression and Trace-Command -Expression script blocks into typed synchronous/once Main execution regions
• bind receiver identity against incoming state, downgrade after observed command-resolution mutation, and retain proof for reviewed module-qualified identities
• propagate current-scope state conservatively across host failure partitions, loop visits, pipelines, and nested direct-call boundaries
• admit version-pinned module-qualified receiver forms only after body visibility is guaranteed
• add focused structural regressions and live PowerShell 7 oracle coverage

Validation

• dotnet build -c Release (0 warnings)
• dotnet test -c Release --no-build (2,097 passed)
• pwsh ./scripts/Add-FileHeaders.ps1 -Verify
• openspec validate v0-3-structured-shell-analysis --strict
• slopwatch analyze -d . --no-baseline --fail-on warning
• git diff --check

Adversarial review

Exact staged patch e6483cd6eb4ab1177399c451eb5a0d4114899a356b81229fc3174941130e2871 received GO after fixing and regression-testing unknown nested-region escape through direct child scope.