update: move issue #401 to DONE after PR #402 emergency merge

Author: krystophny

BACKLOG.md

@@ -15,7 +15,9 @@
 - [ ] #403: Refactor - reduce contour function complexity - functions exceed 50-line target
 
 ## DOING (Current Work)
-- [x] #401: Fix - CI test-coverage failing with segfaults in colored_contours and ascii_heatmap_demo (branch: fix-ci-segfaults-401)
+
+## DONE (Completed)
+- [x] #401: Fix - CI test-coverage failing with segfaults in colored_contours and ascii_heatmap_demo - FIXED: Resolved critical CI segmentation faults in contour plotting functions by replacing unsafe merge() usage with conditional parameter forwarding in matplotlib wrapper, preventing memory access violations when optional parameters are not present (PR #402 merged)
 
 ## FUTURE SPRINTS - Systematic Restoration