## Compass & Map Differentiation
- **Lodestone Compasses**
Added `CompassMeta.getLodestone()` into the sort key so vanilla compasses and lodestone compasses no longer merge.
- **Distinct Maps**
Included `MapMeta.getMapId()` so different map items stay distinct.

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## Robust Metadata Serialization
- **Full Meta Capture**
Switched to serializing the full `ItemMeta` (enchantments, lore, potion data, book data, banner patterns, etc.) into the grouping key, guaranteeing no two items with different metadata ever collapse.