fix: remove all unnecessary animations from all pages

- Remove dead code animations (animate-in, fade-in, slide-in, zoom-in, shake) from tailwindcss-animate plugin (not installed)
- Remove decorative transition effects (transition-all, transition-colors) from all page components
- Remove scale effects (active:scale-95) from buttons
- Remove bounce animations (animate-bounce) from icons
- Keep functional animate-spin on loading spinners as they provide essential loading feedback

Affected pages: Dashboard, Timestamp, Jwt, JsonTools, Base64Converter, HtmlToMarkdown, MarkdownToHtml, QrCode, TextStatistics

pages/JsonTools/DiffResult.tsx

@@ -197,7 +197,7 @@ const UnifiedRow = ({ depth, type, text, active, multiline }: UnifiedRowProps) =
   return (
     <div
       className={cn(
-        'flex items-start w-full font-mono py-0.5 select-text group transition-colors',
+        'flex items-start w-full font-mono py-0.5 select-text group',
         currentTheme.bg,
         currentTheme.text,
         // 4. 高亮定位条：不再使用生硬的蓝圆环，改为现代编辑器的“侧边左高亮带”设计，质感直接拉满