Unit Quantity can be set to zero, causing a DivisionByZeroError when adding the product to the cart

[Huncsuga]

• Lunar version: 1.5.0-beta.6
• Laravel Version: 12.62.0
• PHP Version: 8.4.22
• Database Driver & Version: MariaDB 10.11.18

Expected Behaviour:

The Unit Quantity field on the Inventory tab should not accept values lower than 1.

The field should have a minimum value validation of 1, preventing invalid inventory configurations that can cause division by zero errors.

Actual Behaviour:

The Unit Quantity field currently accepts 0.

When In Stock is set to a value greater than 0 and Unit Quantity is set to 0, attempting to add the product or product variant to the cart results in the following error:

DivisionByZeroError
Division by zero

Steps To Reproduce:

1. Open a product or product variant in the Lunar admin panel.
2. Navigate to the Inventory tab.
3. Set In Stock to a value greater than 0.
4. Set Unit Quantity to 0.
5. Save the changes.
6. Attempt to add the product or product variant to the cart.
7. Observe that a DivisionByZeroError is thrown.