Unify reviewed-safe shell path evaluation

[Aaronontheweb]

Summary

• route the public compatibility path through the same typed candidate path facts used by the coordinator
• remove the obsolete aggregate reviewed-safe implementation and duplicate candidate/path containers
• preserve the declared-shell typed route and the bounded host-style compatibility behavior
• record the cumulative reduction evidence while leaving the complete reduction gate open

Reduction

• 57 fewer production lines
• 4 fewer control-flow lines
• no public or durable-contract change

Validation

• dotnet test src/Netclaw.Actors.Tests/Netclaw.Actors.Tests.csproj -c Release --no-restore: 3,439 passed, 1 expected Windows-only skip
• strict OpenSpec validation for simplify-shell-policy-evaluator and structure-shell-approval-policy
• copyright headers
• git diff --check
• changed-file Slopwatch: 0 issues
• stable patch identity preserved across the Close shell policy coverage states #1960 squash rebase