feat: add Claude devil's advocate review for clustering

Claude now reviews full report content (not just metadata) and:
- Critically evaluates whether groupings make semantic sense
- Identifies false positives (unrelated commits grouped together)
- Identifies false negatives (related commits that should be merged)
- Provides detailed reasoning for each recommendation
- Can split, merge, or reassign reports based on actual content
- Generates a review report (01-claude-review.md) with findings

This is more thorough than simple metadata-based enhancement.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: tychtjan