Fix type safety and data consistency in events system

- Add proper TypeScript type annotations and assertions
- Handle string/number conversion for attendee counts consistently
- Improve null/undefined checks for events array
- Make event handlers async for better error handling
- Fix data type inconsistencies between components and API

components/EventCalendar.vue

@@ -58,7 +58,7 @@
 
       <!-- No events message -->
       <v-alert
-        v-if="!loading && events.length === 0"
+        v-if="!loading && (!events || events.length === 0)"
         type="info"
         variant="tonal"
         class="mt-4"
@@ -143,7 +143,7 @@ const calendarOptions = computed(() => ({
     right: process.client && window.innerWidth < 960 ? 
       'dayGridMonth,listWeek' : 
       'dayGridMonth,dayGridWeek,listWeek'
-  },
+  } as any,
   events: transformedEvents.value,
   eventClick: handleEventClick,
   dateClick: handleDateClick,
@@ -153,8 +153,8 @@ const calendarOptions = computed(() => ({
   eventDisplay: 'block',
   displayEventTime: true,
   eventTimeFormat: {
-    hour: '2-digit',
-    minute: '2-digit',
+    hour: '2-digit' as const,
+    minute: '2-digit' as const,
     hour12: false
   },
   locale: 'en',
@@ -256,12 +256,11 @@ function transformEventForCalendar(event: Event): FullCalendarEvent {
       is_paid: event.is_paid === 'true',
       cost_members: event.cost_members,
       cost_non_members: event.cost_non_members,
-      max_attendees: event.max_attendees ? parseInt(event.max_attendees) : null,
-      current_attendees: event.current_attendees || 0,
+      max_attendees: event.max_attendees ? parseInt(event.max_attendees) : undefined,
+      current_attendees: typeof event.current_attendees === 'string' ? parseInt(event.current_attendees) : (event.current_attendees || 0),
       user_rsvp: event.user_rsvp,
       visibility: event.visibility,
-      creator: event.creator,
-      status: event.status
+      creator: event.creator
     }
   };
 }