refactor: improve type safety by replacing any types with specific interfaces across API services and components.

src/components/calendar/Calendar.tsx

@@ -73,7 +73,16 @@ const Calendar: React.FC = () => {
 
   const handleEventClick = (clickInfo: EventClickArg) => {
     const event = clickInfo.event;
-    setSelectedEvent(event as unknown as CalendarEvent);
+    setSelectedEvent({
+      id: event.id,
+      title: event.title,
+      start: event.startStr,
+      end: event.endStr,
+      extendedProps: {
+        calendar: event.extendedProps.calendar,
+      },
+    } as CalendarEvent);
+
     setEventTitle(event.title);
     setEventStartDate(event.start?.toISOString().split("T")[0] || "");
     setEventEndDate(event.end?.toISOString().split("T")[0] || "");