Backend README (GAME_CLOCK_MS), AGENTS.md notes, TODO items for the open points and the mobile release order; game-history R3.3 and R3.4 marked as replaced. Checked end to end in Chrome: moves, a backend restart, a timeout and the replay.
Each player has 5 minutes; the server keeps the time and a scheduled service ends games whose running clock reaches zero. Replaces the offline turn and inactivity rules.
