Feat: Nested collection groups filters on products

[repl6669]

Summary

Adds a new collection_groups filter to the Products JSON:API schema, enabling filtering products by collections across multiple collection groups simultaneously.

This solves the problem of needing AND logic between collection groups (e.g. "products in category X and season Y") while maintaining OR logic within each group's collection IDs.

Usage

Filter key

filter[collection_groups][{group_handle}][id]={collection_ids}

• {group_handle} — the handle of a CollectionGroup (e.g. product_type, edition, target)
• {collection_ids} — comma-separated collection IDs

Example

GET /api/v1/products?filter[collection_groups][product_type][id]=4&filter[collection_groups][edition][id]=47,46,45&filter[collection_groups][target][id]=20,21

This returns products that:

• Belong to collection 4 in the product_type group, AND
• Belong to collection 47, 46, or 45 in the edition group, AND
• Belong to collection 20 or 21 in the target group

Filtering logic

Scope	Logic
Between groups	AND — product must match all specified groups
Within a group's IDs	OR — product must belong to at least one of the listed collections

Combining with other filters

The new filter works alongside all existing product filters:

GET /api/v1/products?include=thumbnail,lowest_price,collections&filter[collection_groups][category][id]=4&filter[in_stock]=true&filter[brand][id]=1,2

Changes

• New: CollectionGroupFilter — custom JSON:API filter class (packages/api/src/Domain/Products/JsonApi/Filters/CollectionGroupFilter.php)
• Modified: ProductSchema — registered collection_groups filter (packages/api/src/Domain/Products/JsonApi/V1/ProductSchema.php)
• New: CollectionGroupFilterTest — 4 test cases covering single group, OR within group, AND across groups, and no-filter baseline (tests/api/Feature/Domain/Products/JsonApi/V1/CollectionGroupFilterTest.php)