New: fair-play bounds to catch fake scores

Since scores are reported by the game running in the player's browser, they're spoofable — fine for casual boards, annoying if someone posts a nonsense high score. You can now set optional bounds on your game's Leaderboard settings: • Max score — the highest legitimately possible value. • Min score — a floor (handy for lower-is-better games; a puzzle can't be solved in fewer than N moves). • Max per second — for higher-is-better games, the most points earnable per second of play. This one's the strongest: we check it against the actual time played, so "999,999 in four seconds" fails on its own. Anything outside the bounds is silently dropped. Leave a field blank to skip that check. It's a deterrent, not a guarantee — a patient cheat submitting a plausible fake still gets through — but it kills the console-forgery crowd. Details are in the Scores & achievements doc, under Fair-play validation. Rule of thumb: set the per-second rate a little above your true best case, not exactly on it — there's a small grace built in for timing lag.