[Extension] 23. Add a human review queue

[code259]

Goal

Let an authorised reviewer confirm scores and correct incident groups.

Why this matters

Human review is needed for uncertain evidence and for duplicate groups that automation gets wrong.

Work

• Create a queue ordered by review value.
• Record reviewer decisions without overwriting model output.
• Support merge and split corrections with an audit record.
• Keep all changes reversible and attributable.

Done when

A reviewer can resolve one scoring case and one grouping case while preserving the original records.

Priority: First feature to cut.