[Benchmark]: Measure governance version resolution

[rian-be]

Summary

Benchmark governance version resolution so stale request handling, revalidation, and version comparison costs stay visible over time.

Goal

Measure the overhead of resolving approved governance requests against the current state version before execution or terminal request handling continues.

Problem

Governance already models version resolution and stale-request semantics, but that path is not benchmarked as a dedicated runtime surface.

Without a benchmark for version resolution behavior, changes in version comparison, stale detection, revalidation, or request outcome selection can quietly add overhead without being visible in runtime measurements.

Scope

• Benchmark comparing expected and current state versions for governance requests
• Benchmark stale request detection and classification
• Benchmark revalidation-driven request resolution
• Keep the benchmark focused on version resolution behavior rather than execution or storage internals
• Reuse existing governance benchmark helpers where they already exist
• Make scenario names explicit about the version resolution path being measured

Design Expectations

• The benchmark should measure a real version-resolution flow rather than a toy loop.
• Stale and revalidated paths should remain visible where possible.
• Helper code should stay local to the benchmark project.
• Scenario names should make the version-resolution path obvious.

Suggested Measurements

• approved request resolved against matching state version
• approved request rejected as stale
• approved request revalidated before continuing

Acceptance Criteria

• Version resolution is benchmarked as a distinct governance scenario
• Stale detection cost is visible in the benchmark results
• Revalidation cost is visible in the benchmark results
• The benchmark remains centered on governance runtime behavior

Non-Goals

• This issue does not change governance runtime behavior
• This issue does not add provider-specific persistence benchmarks
• This issue does not optimize version resolution prematurely
• This issue does not add full integration or load testing

Notes

This issue is a child of the governance benchmark umbrella #73.