Batch skillXp then resetPerkState with XP rollback; 400 for invalid skillXp;
MasteryFixtureApi gate tests; README fixture vs grant semantics; Bruno GET playerId.
Replace fixture player ids with POST …/__dev/mastery-fixture (resetPerkState,
absolute skillXp). Bruno deny tests set state in pre-request on dev-local-1.
Gated to Development/Testing or Game:EnableMasteryFixtureApi.
GET/POST /game/players/{id}/perk-state with versioned JSON, engine-backed
branch selection, PerkStateApiTests, Bruno collection, README, and E2.M3 alignment.
VinPropane