Clarify the donor-pair wording for RSWT-Bench

README.md

@@ -61,7 +61,7 @@ The viewer shows the `index/` tables. In them, `action_type` is 0 tap, 1 long_pr
 ## RSWT-Bench
 
 RSWT-Bench (Right Screen, Wrong Transition) is a donor-paired benchmark for
-transition verification. Each of 222 credential screens appears once as a
+transition verification. In each of 222 donor pairs, a credential screen appears once as a
 legitimate outcome and once, pixel-identical, as a hijacked one, so any detector
 that sees only the resulting screen scores 0.5 AUC by construction. The test split
 has 966 transitions; the train split has 6,786 for supervised methods.