Add dot indicator to timed month events in custom eventContent

eventContent replaces FC's default inner markup including the dot span.
Render a manual fc-daygrid-event-dot with border-color: var(--event-color).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/calendar/CalendarPage.tsx

@@ -531,6 +531,10 @@ export default function CalendarPage() {
       // Timed events in month: dot + title + time right-aligned
       return (
         <div className="flex items-center gap-1.5 truncate w-full">
+          <span
+            className="fc-daygrid-event-dot"
+            style={{ borderColor: 'var(--event-color)' }}
+          />
           <span className="text-[11px] font-medium truncate">{arg.event.title}</span>
           {repeatIcon}
           <span className="umbra-event-time text-[10px] opacity-50 shrink-0 ml-auto tabular-nums">{arg.timeText}</span>