style: update padding for body and add early return in day detail function

- Adjusted the bottom padding in `style.css` to improve layout by incorporating a comfortable offset for safe areas.
- Added an early return in `dayDetail.js` to prevent further processing when there are no duties or event summaries, enhancing performance and preventing unnecessary DOM manipulations.

webapp/style.css

@@ -246,7 +246,8 @@ body {
   padding-top: 12px;
   padding-left: 16px;
   padding-right: 16px;
-  padding-bottom: max(16px, env(safe-area-inset-bottom));
+  /* Комфортный отступ снизу: safe area + дополнительное поле */
+  padding-bottom: calc(24px + env(safe-area-inset-bottom, 0px));
 }
 
 .day-detail-panel--sheet::before {