feat(CP-2): Conditional Offers Free Product

[aelzakzouk]

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

What is the current behaviour? (You can also link to an open issue here)

What is the new behaviour? (You can also link to the ticket here)

Does this PR introduce a breaking change?

Screenshots (If appropriate)

[sentry]

Bug: The code checks for item.offer.offer_type, but this field does not exist in the data model. The default('') filter causes the condition to always be false.
_{Severity: CRITICAL}

Suggested Fix

The backend API needs to be updated to include the offer_type field in the item.offer object for cart items. Alternatively, if this field is not intended to be added, the new logic depending on it should be removed to avoid the silent failure. The PR should be updated to include any related backend changes.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: src/views/pages/cart.twig#L119

Potential issue: The code introduces a check `(item.offer.offer_type|default('') ==
'cart_offer')` to identify specific promotional items. However, the `offer_type` field
is not part of the documented data structure for the `item.offer` object and appears
nowhere else in the codebase. Because the field is missing, the `default('')` filter is
applied, causing the comparison to always evaluate to `false`. As a result, the
`is_free_cart_offer` variable is never true, which prevents the intended logic of
locking the quantity and hiding the delete button for these promotional items from ever
executing. This allows users to modify or remove items that should be fixed.

_{Did we get this right? 👍 / 👎 to inform future reviews.}