fix(agent): tighten work and verify behavior

[cniska]

Summary

• tighten work and verify instructions so bounded tasks stop earlier
  and verify stays read-only
• pass edited-file scope and reuse targeted test evidence in verify
  to cut rediscovery and duplicate test reruns
• teach test-run to resolve direct counterpart tests from source
  paths so work and verify use the right targeted validation
• remove git-status from the agent surface and add prompt and
  behavior tooling coverage for the slimmer review flow