Add bimodal gap analysis to find_column_boundaries for PDFs with many narrow columns (e.g. 24-column train schedules at 26pt spacing). When a clear gap between within-column jitter and between-column spacing is detected, switch to edge-based clustering with a lower threshold. Also raise heuristic max columns from 15 to 25, and relax column consistency validation for very wide tables (>15 cols). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>