[Sep 23] Hotfix v2: per-account saves, achievement re-sync, boss stutter & more

Thanks for the feedback! This update fixes: 1.Saves being shared between Steam accounts on the same PC — each account now has fully separate saves, judgment collection and archive. Existing saves migrate automatically on first launch; no progress is lost 2.Achievements occasionally never unlocking (an unlock while Steam was unresponsive could be lost permanently — now re-synced automatically on launch) 3.Stutter when entering the final boss fight 4.Seam artifacts on some monster animation frames 5.Card viewer scrollbar style not matching the UI Duplicate names indistinguishable on leaderboards, and the empty "duration" column in local records If you run into anything else, please let us know in the community hub — we'll keep fixing.