Added missing helper functions for all production batch reasoning types:
- create_batch_reasoning_stock_replenishment: Inventory replenishment
- create_batch_reasoning_seasonal_preparation: Seasonal demand prep
- create_batch_reasoning_promotion_event: Promotional events
- create_batch_reasoning_urgent_order: Urgent customer orders
This completes the full set of reasoning helper functions for both
purchase orders and production batches, preventing future import errors
in demo seed scripts and other services.
All helpers now provide structured reasoning_data for i18n translation.
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