refactor(omp): route Herdr policy on demand

[TechDufus]

Summary

• clarify ownership of OMP's always-visible and deferred context layers
• route the Herdr workflow through operation-specific skill:// references while preserving safety and cleanup policy
• enforce a 10% O200kBase token reduction for every route against a frozen pre-refactor fixture

Verification

• python3 roles/omp/tests/test_herdr_workflow.py (24 passed)
• bash roles/omp/tests/test_herd_extension.sh
• bash roles/omp/tests/test_commit_ui_extension.sh
• Ansible sandbox deployment and idempotence (changed=0 on second apply)
• four routed skill:// references resolved through OMP's protocol handler
• git diff --check