feat(settings): emit repo readiness warnings from policy compiler

[JSONbored]

Parent roadmap: #127
Parent phase: #236
Parent epic: #277
Related advanced phase: #269

Goal

Surface repo readiness warnings from focus manifests and repo context before owners invite more contributor traffic.

Requirements

• Emit warnings for risky contribution flow, unclear direct-PR policy, issue-discovery gaps, validation uncertainty, or maintainer-burden concerns.
• Separate public-safe warnings from authenticated/private owner context.
• Keep warnings advisory and previewable.

Acceptance criteria

• Readiness warnings are deterministic and grounded in explicit inputs.
• Public warning text avoids private scoreability, reward/risk, wallet, hotkey, raw trust, and private reviewability.
• Repo owners can see warnings before publication.
• This is not public scoring or autonomous GitHub action.

Validation expected

• Warning fixtures for direct-PR, issue-discovery, validation, and maintainer-burden cases.
• Public/private sanitizer tests.
• npm run test:ci.