Agent skill: draft-and-verify fixes from check --format json

[Connorrmcd6]

Why

The reviewer plugin (#9) judges divergences; it doesn't fix them. drift ships a Claude Code skill that fixes docs from its structured diagnosis. Surface's analog: turn a check --format json divergence into a drafted prose update + re-verify.

What

An agent skill that, given surf check --format json, for each Changed claim: shows old/new code, drafts an updated prose claim for human review, and on approval runs surf verify to re-seal. Advisory/human-in-the-loop; the deterministic core is unchanged.

Depends on

• Version the --format json report contract #16 (versioned JSON contract) so the skill binds to a stable shape.
• Complements Reviewer plugin (LLM over check --format json, advisory-only) #9 (judging) — this is the fixing half.