update: move issue #331 to DONE after PR #353 merge

Author: krystophny

BACKLOG.md

@@ -24,7 +24,6 @@
 - [ ] #350: Refactor - improve documentation comments in raster drawing module
 
 ## DOING (Current Work)
-- [ ] #331: Fix - No legend visible in format_string_demo.html
 
 ## BLOCKED (Infrastructure Issues)
 
@@ -51,6 +50,7 @@
 - Performance impact validation
 
 ## DONE (Completed)
+- [x] #331: Fix - No legend visible in format_string_demo.html - FIXED: Restored legend visibility by removing automatic reset of show_legend during figure re-initialization, allowing user legend settings to persist across plot operations (PR #353 merged)
 - [x] #334: Fix - No output visible on pcolormesh_demo.html - FIXED: Added comprehensive documentation content with PNG images, ASCII outputs, and PDF download links to resolve GitHub Pages visibility issue (PR #351 merged)
 - [x] #333: Fix - Circles seem not centered with line plot in marker_demo.html - FIXED: Resolved marker centering coordinate consistency through sub-pixel adjustment (-0.5, -0.5) to align markers with line drawing pixel centers (PR #346 merged)
 - [x] #335: Fix - Axes wrong and no labels visible on scale_examples.html - FIXED: Resolved axis label rendering issues with proper tick marks, axis labels, and tick labels in ASCII and raster backends (PR #341 merged)