refactor: extract repeated star formatting logic

- Extract formattedStars calculation to avoid duplication
- Keep tabular-nums span for consistent number width during animation
- Address code review feedback from @xqliu
Co-Authored-By: tinkle-community <tinklefund@gmail.com>

web/src/components/landing/HeroSection.tsx

@@ -22,6 +22,9 @@ export default function HeroSection({ language }: HeroSectionProps) {
     duration: 2000,
   })
 
+  // 格式化 stars 显示
+  const formattedStars = (animatedStars / 1000).toFixed(1)
+
   const fadeInUp = {
     initial: { opacity: 0, y: 60 },
     animate: { opacity: 1, y: 0 },
@@ -48,12 +51,12 @@ export default function HeroSection({ language }: HeroSectionProps) {
                   ) : language === 'zh' ? (
                     <>
                       {daysOld} 天内{' '}
-                      <span className='inline-block tabular-nums'>{(animatedStars / 1000).toFixed(1)}</span>
+                      <span className='inline-block tabular-nums'>{formattedStars}</span>
                       K+ GitHub Stars
                     </>
                   ) : (
                     <>
-                      <span className='inline-block tabular-nums'>{(animatedStars / 1000).toFixed(1)}</span>
+                      <span className='inline-block tabular-nums'>{formattedStars}</span>
                       K+ GitHub Stars in {daysOld} days
                     </>
                   )}