Stock Valuation, FIFO/LIFO/Average & Batch/Serial Tracking

We've activated stock valuation and tracking across the application. The update includes:

• Valuation methods: FIFO (First-In-First-Out), LIFO (Last-In-First-Out), and Average cost applied on entries and withdrawals with layer consumption and product cost update.
• Tracking types: Basic (quantity only), Batch (+ optional expiry date for items with batch tracking), and Serial number.

  Batch and serial are entered or selected in the Stock impact modal, not on the document lines.

• Product valuation tab: New tab on the product page with summary cards (method, current cost, total quantity, stock value) and cost history table (entries and withdrawals with type, reference, warehouse, batch/serial, quantity, unit price, value).
• Stock movements: Movements list and product Entrepôts tab show all movement types (entry, withdrawal, transfer, adjustment, inventory, rebut, manufacture) with optional Batch, Expiry and Serial number columns.