Implement explainable ranking with human review

[sudoantonio]

Objective

Rank compatible calls only after hard constraints, and expose the reason for each
score to a human reviewer.

Acceptance criteria

• Eligibility blockers are evaluated before numeric ranking.
• Score contributions, missing data and uncertainty are visible per result.
• A reviewer can confirm, correct or reject a recommendation with a rationale.
• Ranking configuration and review outcome are serializable and reproducible.