fix(hermes): A percentage must be divided by 100 before subtracting it from 1. This one-line change produces the expected 90.0, 0.0, and 16.99 results without changing validation or rounding behavior. (incident hermes-code-demo/4)

src/discount.py

@@ -10,4 +10,4 @@ def apply_discount(subtotal: float, percent: float) -> float:
 
     if percent < 0 or percent > 100:
         raise ValueError("percent must be between 0 and 100")
-    return round(subtotal * (1 - percent / 10), 2)
+    return round(subtotal * (1 - percent / 100), 2)