Offline v4 holdout probe. Last round's width=window result was the
no-elimination metric; production still-valid ranges after six answers
are 15/33/56 minutes. Adjacent merge never fires under step-2 radii.
W1/W2 match baseline; W3 is uncertain after one coverage squeeze.
No production clustering or scoring defaults changed.
Build holdout v4 from the public AA set, correct the two v3 dates, and sweep
R1–R5 plus pairs offline. No production scoring defaults change. No
implementation brief: delivered width stays the full window on every radius.