Supply Drop Limiter

Unbounded dictionary growth — Added a CleanupStaleEntries() method on a configurable timer (default every 300s). It prunes expired timestamps and removes player keys with empty lists, so the dictionary doesn't grow forever over a wipe. The timer is properly destroyed on Unload(). The cleanup interval is exposed in config as CleanupIntervalSeconds. Double-processing guard — Added if (entity.IsDestroyed) return; early in OnExplosiveThrown so if both OnExplosiveDropped and OnExplosiveThrown fire for the same throw, the second call bails immediately instead of trying to kill an already-dead entity. GC pressure from RemoveAll lambda — Replaced history.RemoveAll(t => t < cutoff) with a manual reverse for loop in PruneHistory and in the cleanup method. No delegate allocation per call anymore. Reusable cleanup list — _keysToRemove is a class-level list that gets reused each cleanup cycle instead of allocating a new List<ulong> every 5 minutes.

Initial release