Replaces the vanilla continuous wool system with a realistic twice-yearly shearing model.

Sheep are sheared in April and October. Wool accumulates over the full 6-month period between shearings. Animal health is tracked monthly — unhealthy sheep produce proportionally less wool.

Features:
- Twice-yearly shearing (April and October)
- Health-averaged wool calculation across the full accumulation period
- Configurable shearing cost per sheep (default $5)
- All notifications individually toggleable in the Settings menu

Settings are found in the in-game Settings menu under "Seasonal Wool Production".