Ratify Infigraph pilot governance and measurement

[wryenmeek]

What to build

Ratify the knowledgebase Infigraph pilot's governance, success measures, and promotion criteria after the implementation slices are available for review.

Acceptance criteria

• The pilot scope is explicitly knowledgebase-only, CLI-only, Locality 2, and limited to the approved qualifying paths.
• CI-7 is documented as advisory/non-merge-blocking for merges while still failing when required Infigraph analysis cannot run or cannot produce valid evidence.
• The existing commit-bound cross-functional review receipt remains the only review-evidence gate; no second merge gate is introduced.
• The pilot measures availability, freshness, runtime, false positives, missed impacts, reviewer usefulness, and receipt coverage across at least 10 qualifying pull requests.
• Promotion thresholds and the decision owner are recorded, with MCP parity, cross-repository rollout, and merge-blocking findings explicitly deferred.

Blocked by

• Add the knowledgebase CI-7 advisory analysis #598
• Integrate Infigraph into the existing review receipt #599
• Add the fast local Infigraph pre-commit warning path #600
• Add CLI-only agent guidance for knowledgebase #601