Handle PowerShell split/index/join projections and pin remaining approval prompts

[Aaronontheweb]

Summary

• harvest and sanitize all 14 PowerShell shell-approval prompt shapes from the two post-deployment consumer sessions
• add generator-owned integration entries 549-562, all parseable with 39 complete command occurrences
• recognize one bounded ($_ -split literal)[integer-range] -join literal script-block projection without evaluating it
• keep dynamic operands, nested execution, mutations, methods, separators, and unsupported variants fail-closed
• anonymize older consumer/product-labelled Bash entries and expand the PII gate to every JSON string and filename

Assessment

Thirteen prompt shapes were already fully represented by SST and point to downstream policy/catalog behavior. One prompt exposed an SST structural gap in the bounded split/index/join projection; this PR closes only that narrow gap.

Validation

• dotnet tool restore
• dotnet build -c Release --no-restore (0 warnings)
• dotnet test -c Release --no-build --no-restore (3,362 passed)
• pwsh ./scripts/Add-FileHeaders.ps1 -Verify
• Slopwatch on all modified C# files (0 findings)
• fresh 562-entry generator run; entries 549-562 match exactly
• independent adversarial parser and corpus privacy review

No release or package publication is included.