Speed Receipt Tick

Recompute the median time to shortlist (Epic 5.7).

The ONLY writer of the stat www reads. Computing nightly rather than per request is what stops a published number moving between the page a buyer reads and the email they forward five minutes later.

Returning eligible: false is a normal outcome — small sample, or a month that did not beat the 72-hour promise. Every surface falls back to the plain guarantee copy, which is true regardless.