Decision
Products as project definitions
Decided and shipped: products live in project metadata, and nodes keep their own platforms.
The Products RFC settled on products as project-level definitions: each product has an id, a title and the platforms it ships on. Flows and screens carry their product; acceptances derive it from what they cover; data models and endpoints derive it from the screens that reach them. A node may only target platforms its product ships on.
It shipped right after the decision. Per-target flattening and product-as-node were both rejected, and a per-surface product override stays deferred until someone actually needs it.