Complete required exhaustive CI cutover

[selmanays]

Summary

• promote the dependency-aware 130-workload exhaustive runner to the required CI path
• preserve an explicit manual legacy rollback mode while removing the completed shadow workflow and migration adapter
• publish the immutable I07-02 equivalence baseline and close DEBT-008
• update roadmap, status, README, testing standards, ADR, and infrastructure-debt ownership

Evidence

• hosted same-revision comparison: required and retained legacy paths both passed 130 workloads across 61 proof pairs
• official required CI after cutover: 130/130 passed; the legacy rollback job was skipped by default
• final clean local gate on 4b4e24a: REQUIRED / EXHAUSTIVE, 130/130 passed, 61 proof pairs, tracked workspace unchanged
• focused closure preflight: 117/117 passed

Migration state

I07-02 is complete. Required exhaustive CI is authoritative. The retained legacy path is manual rollback authority only and remains tracked by DEBT-007. M07-T02 is the next planned task.