Adds region-based layout support for screens: steps now carry region information, and the server packs regions into dedicated bands with per-region captions. UI changes introduce RegionCaption and region-aware step rendering; StepsModel and related views (StepsView) consume region data, while the region-aware layout keeps anchor and region boundaries intact. Tests and docs updated to reflect region-driven organization and visualization of screen regions. This enables visualizing a screen’s picture as region-based columns rather than a single distance-driven row.