feat(pos): update sale invoice creation to include customer and item details
feat(pos): enhance POS account service to include today's sales information
feat(pos): refactor order DTO to create sale invoice with detailed item structure
feat(products): add minimum stock alert level to product creation and update DTOs
fix(triggers): implement stock validation and movement logging for sales invoice items
refactor(database): update sales invoices schema to include posAccountId and remove inventoryId
