refactor: Extract time formatting utility

Extracts elapsed time formatting logic into a reusable utility function
that handles seconds, minutes, and hours display.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: brandonkachen

cli/src/components/elapsed-timer.tsx

@@ -2,6 +2,7 @@ import { useEffect, useState } from 'react'
 import { TextAttributes } from '@opentui/core'
 
 import { useTheme } from '../hooks/use-theme'
+import { formatElapsedTime } from '../utils/format-elapsed-time'
 
 interface ElapsedTimerProps {
   startTime: number | null
@@ -54,7 +55,7 @@ export const ElapsedTimer = ({
 
   return (
     <span fg={theme.secondary} attributes={attributes}>
-      {elapsedSeconds}s{suffix}
+      {formatElapsedTime(elapsedSeconds)}{suffix}
     </span>
   )
 }

cli/src/utils/format-elapsed-time.ts

@@ -0,0 +1,19 @@
+/**
+ * Format elapsed seconds into a human-readable string.
+ * - Under 60 seconds: "Xs"
+ * - 60-3599 seconds (1-59 minutes): "Xm"
+ * - 3600+ seconds (1+ hours): "Xh"
+ */
+export const formatElapsedTime = (elapsedSeconds: number): string => {
+  if (elapsedSeconds < 60) {
+    return `${elapsedSeconds}s`
+  }
+  
+  if (elapsedSeconds < 3600) {
+    const minutes = Math.floor(elapsedSeconds / 60)
+    return `${minutes}m`
+  }
+  
+  const hours = Math.floor(elapsedSeconds / 3600)
+  return `${hours}h`
+}