nx_game_save.nx

nx_game_save.nx -- SOVEREIGN SAVE / LOAD for game state. Built because the gamebench ruler ranks save-load-persistence as the #1 blocker across the ingested corpus (11 of 12 real titles need it), i.e. this is demand-ranked by measurement, not chosen by taste. STATE IS AN i64 VECTOR, so this is game-agnostic: any game that can describe itself as integers can use it. THE CONTRACT -- a save file is either loaded EXACTLY or REFUSED WITH A REASON. It is never partially applied and never silently accepted when damaged, because a corrupted save that half-loads is worse than one that fails: it strands the player in an impossible world state and looks like a game bug forever. Layout (all i64, little-endian): [magic][version][count][payload...][checksum-of-everything-before]. license_tier: ORIGINAL