- Increase white threshold from 0.95 to 0.98 (pure white only)
- Decrease black threshold from 0.05 to 0.02 (pure black only)
- Remove "other solid" detection (caused false positives on gray backgrounds)
This prevents light gray table cell backgrounds (RGB ~0.93) from being
incorrectly detected as covering/redaction rectangles.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>