Event search (Ctrl+F), locale/RTL handling, weekday selector workday/weekend, refactored event handling, Firefox compatibility (#3)

Major refactoring for cleanup, with various bugfixes.

Weekday selector in Settings now shows workdays/weekend bars based on current locale (also used to choose default values). Weekday selector in event dialog uses the days set in settings, as expected.

src/assets/layout.css

@@ -131,7 +131,7 @@ header {
   overflow: visible;
   position: absolute;
   top: 0;
-  right: 0;
+  inset-inline-end: 0;
   width: 100%;
 }
 .month-name-label > span {