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

composables/useEvents.ts

@@ -113,7 +113,7 @@ export const useEvents = () => {
     error.value = null;
 
     try {
-      const response = await $fetch(`/api/events/${eventId}/rsvp`, {
+      const response = await $fetch<{ success: boolean; data: any; message: string }>(`/api/events/${eventId}/rsvp`, {
         method: 'POST',
         body: {
           ...rsvpData,
@@ -130,8 +130,10 @@ export const useEvents = () => {
           
           // Update attendee count if confirmed
           if (rsvpData.rsvp_status === 'confirmed') {
-            const currentCount = events.value[eventIndex].current_attendees || 0;
-            events.value[eventIndex].current_attendees = currentCount + 1;
+            const currentCount = typeof events.value[eventIndex].current_attendees === 'string' 
+              ? parseInt(events.value[eventIndex].current_attendees) || 0
+              : events.value[eventIndex].current_attendees || 0;
+            events.value[eventIndex].current_attendees = (currentCount + 1).toString();
           }
         }