Adds support for completable task events

Enables marking scheduled events as complete based on a new "event-type" tag.

This change introduces the concept of "completable" events, specifically for events of type "task". It modifies the ScheduledEventCard component to:

- Display completion information only for completable events
- Show the "Mark Complete" button only for completable events that are not yet completed
- Adjust the opacity and strikethrough styling based on the event's completable and completed status.

The ScheduledEventService is updated to extract the event type from the "event-type" tag.

src/modules/nostr-feed/services/ScheduledEventService.ts

@@ -15,6 +15,7 @@ export interface ScheduledEvent {
   description?: string
   location?: string
   status: string
+  eventType?: string // 'task' for completable events, 'announcement' for informational
   content: string
   tags: string[][]
 }
@@ -76,6 +77,7 @@ export class ScheduledEventService extends BaseService {
       const description = event.tags.find(tag => tag[0] === 'description')?.[1]
       const location = event.tags.find(tag => tag[0] === 'location')?.[1]
       const status = event.tags.find(tag => tag[0] === 'status')?.[1] || 'pending'
+      const eventType = event.tags.find(tag => tag[0] === 'event-type')?.[1]
 
       if (!start) {
         console.warn('Scheduled event missing start date:', event.id)
@@ -96,6 +98,7 @@ export class ScheduledEventService extends BaseService {
         description,
         location,
         status,
+        eventType,
         content: event.content,
         tags: event.tags
       }