- sokoban.html: canvas game, entrance/exit door mechanic (level completes
by walking to the exit after all boxes are placed, not an alert popup),
solution search UI (modal with timer, cancel, "Решение найдено!" button)
- solver.js: A* with binary heap, true-distance heuristic, static
deadlock cells, freeze-deadlock detection, tunnel macro-moves,
chunked step() API for non-blocking search in the UI
- localStorage-backed solution leaderboard per level (fewest moves wins),
fed by both solver finds and manual player completions; G replays the
best recorded solution
- BACKLOG.md: known follow-ups (dead files, room/corral pruning, undo, etc.)
