Fixed: no upload link when calling back about an existing refund

On Pro, the AI can email a customer a secure link to send photos of a damaged item. It was only doing so when the refund was brand new — so the one caller most likely to be asked for evidence, somebody ringing back about a refund already in progress, was the one caller who never got a link. They now get one, and if a link was already sent the AI points them back to it rather than issuing a second. The AI also no longer mentions a link when there is no email address to send it to.