didericis
88031c9d73
Adds search_counterexample_comprehensive iterating Sage's planar_graphs generator across all maximal planar graphs of bounded order. Exhaustive enumeration through order 13 (9150+49566 triangulations) yields exactly one graph with no plane diamond coloring, at order 13. Updates Theorem 2.6 to assert minimality and uniqueness, and replaces the figure and edge list with the smaller counterexample. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>