- Fix StaticGuard ignoring litCells and RotatingGuard not lighting
facing direction
- Fix guard cleanup leak (direction indicators not destroyed)
- Add centralized theme system with dark stealth aesthetic
- Add scene fade transitions and level completion animation
- Add level progress persistence via localStorage
- Add turn counter, locked/completed level states in LevelSelect
- Redesign 12 levels across 6-act narrative arc with per-level story
- Add LevelIntro scene showing story text before each level
- Add bilingual (EN/VI) level story descriptions
- Remove dead code (counter.js, duplicate game/main.js)
- Initialize project docs (overview, architecture, code standards)
