test(benchmarks): consolidate product verification

[thejustinwalsh]

Summary

• fold Presentation control coverage into the maintained all-workloads browser probe
• share one source-boundary scanner across benchmark dependency rules
• remove duplicate registry enumeration and brittle source-string/self-tests while retaining product-level lifecycle, target, and renderer-state gates

Verification

• 60 benchmark test files / 318 tests passed
• the changed Chromium comparison route completed all 21 workload/technique cells and the merged Presentation assertions
• benchmark typecheck, lint, format, and OKF documentation validation passed

This is PR 1 of 3 in the workflow-cleanup checkpoint.