Add optimization contribution closeout

[sarthakagrawal927]

Closes #111

Summary

• Challenge a kept optimization before publication.
• Compare simpler candidates across target and available control metrics.
• Bind campaign, candidate SHA, optional T-Rex receipt, checks, approvals, and review threads in one fail-closed receipt.
• Invalidate stale publications and preserve revision-bound maintainer learning.
• Add closed CLI/MCP operations for challenge, inspection, and explicit refresh.

Marked showed why: a real speedup can coexist with unnecessary state, outdated inline feedback, and fork checks that require approval rather than indicate code failure.

GitHub access is read-only. This adds no polling, comments, review requests, merges, deploys, app install, or maintainer configuration.

Validation

• 134 runtime tests
• Biome on touched code
• docs and all 56 OpenSpec items
• live read-only classification of perf: optimize reference link masking markedjs/marked#4048