- Add ItemTrackingType (SERIALIZED/BATCH), ItemCondition, MovementType, LocationType enums
- Add InventoryItem model with dual tracking (serialized by serial number, batch by quantity)
- Add StockMovement model as immutable movement ledger (no updatedAt)
- Add recordedMovements relation on User model
- Indexes on tenantId, itemType, trackingType, inventoryItemId, movementType
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>