[feat] CV validation API

[erikbayerlein]

Epic: #70 (Validação de CV)
Use Case: #65

Fase 2 — Implementação posterior à fase de inscrição.

Description

API for professors and secretary to validate candidate CV scores.

Acceptance Criteria

• Professor can view CV data of candidates enrolled in their themes.
• Secretary can view CV data of all candidates.
• Validator can accept or modify the score for each CV item.
• System stores both declared score (candidate) and validated score (validator).
• Audit trail records: validator userId, role, timestamp, original and modified scores.
• Validated score is used for final classification.
• Validation status per candidate is tracked (pending/validated).