[Task]: Expand governance benchmark coverage

[rian-be]

Summary

Expand the benchmark coverage for the governance runtime so request lifecycle, approval, version resolution, and governed execution costs stay visible as the package evolves.

Goal

Provide governance benchmark umbrella that can be used to track request lifecycle, approval workflow, version resolution, governed execution, and governance read/query costs as the codebase changes.

Problem

The governance package already contains request lifecycle, approval workflow, version resolution, governed execution, and query oriented runtime behavior, but those paths are not benchmarked as dedicated performance surface.

Without a governance benchmark umbrella, it becomes harder to tell whether changes improve the runtime contract or quietly add overhead in approval, storage, resolution, or query paths.

Scope

• Review the current governance runtime hotspots and identify which paths deserve benchmark coverage
• Add benchmark coverage for request lifecycle transitions
• Add benchmark coverage for approval workflow overhead
• Add benchmark coverage for version resolution and governed execution
• Add benchmark coverage for governance query or read paths where they materially affect runtime behavior
• Keep the benchmark scope centered on the governance runtime rather than the core engine or provider-specific concerns
• Split follow-up work into smaller benchmark issues once the target scenario is clear

Design Expectations

• Benchmarks should measure meaningful governance runtime behavior rather than synthetic micro optimizations.
• Each benchmark should map to a real governance concern.
• Scenario names should reflect the path being measured.
• The benchmark project should stay easy to extend as new governance surfaces are added.
• If benchmark data requires setup helpers, those helpers should stay local to the benchmark domain.

Suggested Coverage Surface

• request lifecycle transitions
• approval workflow actions
• version resolution and governed execution
• governance query and read performance
• governance side effect and decision materialization where relevant

Acceptance Criteria

• The governance runtime has a clear benchmark roadmap for the hotspots that matter most
• Governance performance can be measured across more than one execution shape
• Benchmark scenarios are named and organized by governance concern
• Follow-up benchmark work can be split into focused subissues without rewriting the umbrella issue
• The benchmark scope stays centered on governance runtime behavior

Non-Goals

• This issue does not change runtime behavior
• This issue does not add benchmark coverage for every example or provider
• This issue does not require full performance lab or load testing environment
• This issue does not optimize code just to make benchmarks look better

Notes

This issue is intended as a governance benchmark umbrella under the broader benchmark work.