# CON-004 Lab — Approval Event & Current Validity

Implement `evaluate(case)` in `starter.py`. Keep the approval event unchanged. Derive the present state from exact subject, effective policy, validity window, and status events effective at the request timestamp.

Return eight fields: `decision`, `current_validity`, `reason`, `subject_ok`, `policy_ok`, `time_ok`, `status_epoch_ok`, and `history_immutable`.