fix: Refine pace status logic in MetricLineRenderer

- Updated the condition for determining pace status to include a check for periodDurationMs, ensuring "ahead" is only shown when usage is zero and a valid period duration exists.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/provider-card.tsx

@@ -336,7 +336,7 @@ function MetricLineRenderer({
           )
         : null
     const paceStatus: PaceStatus | null =
-      line.used === 0 ? "ahead" : (paceResult?.status ?? null)
+      line.used === 0 && line.periodDurationMs ? "ahead" : (paceResult?.status ?? null)
 
     return (
       <div>