List modifier products

## Get products for a modifier Returns the products currently linked to the modifier `:modifierId`. It is the read counterpart of `POST /product-modifiers/products/link`. ### Authentication - Merchant API key in **`x-api-key`** (alias `x-account-api-key`). - Requires **`Merchant.product.read`**. ### Path params - `modifierId` — the modifier UUID. Must belong to your store, otherwise **400 Bad Request** (`Modifier not found in yours`). ### Response A bare array of full product objects (no pagination envelope). There is **no request body**. --- **Notas:** Handler: productModifiersService.getProductsForModifier. Returns a bare array read through the productModifiers join table. Inverse view of GET /v1/products/:productId/modifiers.