nx_plotgen.nx

nx_plotgen.nx -- the SOVEREIGN PLOT GENERATOR. nx_gamebench hard GAP: nx_story_vm EXECUTES authored story graphs but NOTHING GENERATED them, and the operator named "our own plot generator" explicitly. Feeds the Monster Girl Island / Strive: Conquest north-star outputs. Emits a graph in the EXACT format nx_story_vm already consumes (ch_target / ch_req / ch_set / node_is_end, SV_NCH choices per node) -- so generated plots run on the existing VM with no adapter. Generation and execution stay separate organs; this one only writes DATA. ★THE BUG THIS KILLS -- the UNWINNABLE QUEST. Procedural narrative's defining failure is emitting a story whose ending is gated behind a flag no reachable path can set: the player needs a key that does not exist. Here solvability is STRUCTURAL, not tested-for afterwards: - a MAIN SPINE 0 -> 1 -> ... -> ending is laid down first, and its advance choice is ALWAYS choice 0 with NO flag requirement, so the spine is unconditionally walkable; - every spine node RAISES a flag bit as you pass it; - a gated branch at spine node k may only REQUIRE bits raised by spine nodes STRICTLY BEFORE k. Therefore walking the spine always satisfies every gate it meets and always reaches an ending -- the generator cannot emit an unwinnable plot, and the gate proves it by actually WALKING the graph via sv_choose rather than by inspecting it. Also: deterministic (same seed -> same plot, so a story is reproducible from its seed alone) and varied (different seeds -> materially different plots, not one template with names swapped). LIB ONLY -- no main() by ecosystem convention. license_tier: ORIGINAL expect_exit: 0