What this build is measuring

• identity_override — how often someone rejects the identity the quiz gave them. High means the taxonomy is wrong.
• soldout_recovery — of people who open a sold piece, how many click an alternative instead of leaving. The core metric.
• borrow_start / borrow_end — which identities get borrowed, and from where. Tells you whether occasion mode is real.
• quiz_complete — target 65% of starts. Below that, fix structure before content.
• rail_depth — items live per identity per size, logged on every shop view. Below roughly 15 the rail feels empty.