Outbound Interstitial

The branded page a buyer sees on the way to a store.

It deliberately does NOT log the click and does NOT know the destination. Both belong to /go below, and splitting them is what makes the page safe to show:

• The tagged URL stays server-side. Putting it in this document would undo the reason the redirect exists at all — build_affiliate_url runs on the server so the affiliate id is never somewhere it can be read off the page or stripped by an extension.
• A click means a buyer who actually left. Anything that merely FETCHES this page — a crawler, a link preview, a browser prefetching on hover — gets HTML and stops there. Under the old single-endpoint design every one of those wrote an outbound_clicks row indistinguishable from a sale.

Set GCG_INTERSTITIAL_DELAY_MS=0 to bypass it entirely and go straight to the store. This sits between a buyer and a purchase, so it needs a kill switch that does not require a deploy.