FS25 Forage Wagon Fill Lock v0.1.0.5

PURPOSE
Locks the first supported grass or hay type collected until the wagon is emptied.

BEHAVIOUR
- More of the SAME fill type collects normally.
- Hay is ignored while Grass is already loaded.
- Grass is ignored while Hay is already loaded.
- Fresh/dry Clover and Alfalfa variants are kept separate when those fill types exist.
- Empty wagons and wagons containing unsupported material retain normal game behaviour.
- Uses a global forage-wagon hook so standard and custom inherited wagon types are covered.

SUPPORTED FILL TYPES
- Grass: GRASS_WINDROW
- Hay: DRYGRASS_WINDROW
- Clover / Clover Hay: CLOVER_WINDROW / DRYCLOVER_WINDROW (modded maps)
- Alfalfa / Alfalfa Hay: ALFALFA_WINDROW / DRYALFALFA_WINDROW (modded maps)
