feat: implement day detail panel for calendar

- Introduced a new `dayDetail.js` module to manage the day detail panel functionality, allowing users to view detailed information about duties and events for each calendar day.
- Enhanced the calendar rendering in `calendar.js` to include visual indicators for duties and events, improving user interaction and experience.
- Updated CSS in `style.css` to style the day detail panel and its components, ensuring a responsive design for both desktop and mobile views.
- Refactored `hints.js` to export the `getDutyMarkerRows` function, facilitating better integration with the new day detail features.
- Added localization support for the day detail panel in `i18n.js`, including new translations for close button and event titles.
- Enhanced the initialization process in `main.js` to set up the day detail panel on application load.

webapp/js/i18n.js

@@ -48,7 +48,8 @@ export const MESSAGES = {
     "hint.from": "from",
     "hint.to": "until",
     "hint.duty_title": "Duty:",
-    "hint.events": "Events:"
+    "hint.events": "Events:",
+    "day_detail.close": "Close"
   },
   ru: {
     "app.title": "Календарь дежурств",
@@ -92,7 +93,8 @@ export const MESSAGES = {
     "hint.from": "с",
     "hint.to": "до",
     "hint.duty_title": "Дежурство:",
-    "hint.events": "События:"
+    "hint.events": "События:",
+    "day_detail.close": "Закрыть"
   }
 };