Rebuild the in-game HUD on UI Toolkit (HudUi/HudSystem, Aether palette) consistent with the menu; build-palette bar (BuildPaletteState) drives cursor->cell ground-ghost preview (green/red via BuildPreviewMath), left-click place / right-click cancel / rotate; fire suppressed in build mode; combat juice restyle. +4 BuildPreviewMath EditMode tests.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
