Novelty effect over four weeks

Shopee launched a new home-feed layout and the first week looked spectacular. A novelty effect is when users engage with something because it's *new*, not because it's *better* — the lift decays as the novelty wears off, so a test stopped after week one ships a change that does nothing.

From weekly_ab, return each week with lift — the treatment conversion rate minus the control conversion rate — rounded to 4 decimal places. Order by week.