fix: clampUsd function behavior to match JSDoc

Return 0 immediately for NaN values instead of clamping NaN->0->1,
making the actual behavior consistent with the documented behavior.

src/base/credits/comfyCredits.ts

@@ -137,6 +137,6 @@ export const formatUsdFromCents = ({
  * @returns The clamped value between $1 and $1000, or 0 if NaN
  */
 export const clampUsd = (value: number): number => {
-  const safe = Number.isNaN(value) ? 0 : value
-  return Math.min(1000, Math.max(1, safe))
+  if (Number.isNaN(value)) return 0
+  return Math.min(1000, Math.max(1, value))
 }