Fix proof-aware native review flow

[BaseInfinity]

Closes #73

Summary

• run the maintainer broad proof once through the proof-stamping entrypoint
• bind prompt-only review to exact base and candidate identities
• migrate managed consumer guidance through policy schema 3
• keep reviewers code-review-only and prohibit redundant broad-suite reruns

Verification

• 11/11 proof groups passed on candidate tree 3ed64ed8d96fa2005b949c2238e9898fb11e12f5
• Sol High: no blocking findings
• Fable High: no blocking findings
• bounded at two corrective rounds; no reconciliation needed