bump: minor
type: feat
Gameplay-controller foundation (#57) — the shared, cross-genre building blocks the builtin controllers stand on, shipped as the source package **ludic.gameplay**: a deterministic `Cooldown` frame timer (engine-ticked), a `Stats` attribute bundle with an unbounded timed **modifier stack** (`Stats.total` computes base+flat then percent on demand; expired modifiers self-despawn), a `Faction` friend/enemy/neutral relationship table (same-id-friendly / different-hostile by default), and a `Combat` damage pipeline whose `cancellable DamageAboutToApply` hook lets a game veto a hit *or rewrite the amount* (`Combat.set_amount`) and which emits `Damaged`/`Died`/`Healed`. Everything is integer-only so lockstep, replay and `world_save` snapshots hold. Also adds extensibility **lever 5** to the language: `disable system <esys_fn>` drops exactly one engine-owned system's tick at compile time, so a game can carry a well-known component but tick it with its own handler (byte-identical when nothing is disabled; the C-free bootstrap fixpoint is untouched). Example: `examples/library/gameplay_foundation.ludic`.