v0.6.2 — /verify-design single-pass + model fit

Fixed

• `/verify-design` documents itself as a single-pass fidelity-fix skill, not a review-only gate. Empirically, dispatching it as review + separate fix doubles Paper MCP and Playwright load for the same outcome — the skill already does review + fix + re-verify in one pass.
• Adds a model-fit matrix for parent agents that dispatch this skill to sub-agents:
  • Sonnet for first-pass delta work on a new/changed PR
  • Haiku for re-verify against a known delta list
  • Opus only for from-scratch design + implementation
• Direct user invocations run at the user's chosen model — no auto-downgrade for cost.