bug(billing): plan product listings return the product title as its behavior

[rohilsurana]

What

BillingPlanRepository.ListWithProducts (internal/store/postgres/billing_plan_repository.go:380) builds its SELECT with:

prd.Col("title").As("product_behavior"),

So the product_behavior column is filled from the product's title, not its behavior column. The billing_products table does have a real behavior column (migration 20231231021142_add_feature_behavior, mapped at billing_product_repository.go:52). As a result every product returned by ListPlans, GetPlan, and the new ListAllPlans reports behavior equal to its title.

The same block also sources plan_deleted_at from the product table (billing_plan_repository.go:374, prd.Col("deleted_at").As("plan_deleted_at")), which looks wrong for a plan's deleted-at and is worth reviewing at the same time.

Impact

Any consumer that reads a product's behavior from a plan listing gets the title instead of the behavior. Pre-existing; it was surfaced while reviewing the new ListAllPlans endpoint.

Fix

Select prd.Col("behavior").As("product_behavior") and review the plan_deleted_at source. Add a repository test that asserts the behavior round-trips.