@hatch:ecs v0.2.5

Entity-component-system for Wren. World storage + fluent Query.with(C).without(C) filters, component-instance bundles for one-call spawns, typed Resources and Events<T>, deferred Commands for safe mid-loop mutation, hierarchy via setParent / childrenOf, onAdd / onRemove lifecycle hooks, and a Schedule with before / after ordering for system dispatch. SaveSystem.snapshot(world, components) + SaveSystem.restore(...) round-trip ECS state through plain Maps ready for JSON. Pure Wren — composes with @hatch:game's frame loop, runs anywhere Wren runs.