refactor: Update useMarket composable to utilize fetchEvents method and improve subscription handling

- Replace direct calls to fetchNotes with the new fetchEvents method in useMarket.ts for better event retrieval.
- Simplify event fetching logic by removing unnecessary filters and enhancing clarity.
- Implement individual relay subscriptions for market updates, allowing for more efficient event handling and cleanup.

src/lib/nostr/client.ts

@@ -29,6 +29,10 @@ export class NostrClient {
     return this._isConnected
   }
 
+  get poolInstance(): SimplePool {
+    return this.pool
+  }
+
   async connect(): Promise<void> {
     try {
       // Try to connect to at least one relay
@@ -205,6 +209,67 @@ export class NostrClient {
     }
   }
 
+  /**
+   * Fetch events by kind
+   */
+  async fetchEvents(options: {
+    kinds: number[]
+    authors?: string[]
+    limit?: number
+    since?: number
+    until?: number
+    '#d'?: string[]
+  } = {}): Promise<Event[]> {
+    const {
+      kinds,
+      authors,
+      limit = 100,
+      since,
+      until,
+      '#d': dTags
+    } = options
+
+    const filters: Filter[] = [{
+      kinds,
+      limit,
+      ...(authors && { authors }),
+      ...(since && { since }),
+      ...(until && { until }),
+      ...(dTags && { '#d': dTags })
+    }]
+
+    try {
+      const allEvents: Event[] = []
+      
+      const subscription = this.pool.subscribeMany(this.relays, filters, {
+        onevent(event: Event) {
+          allEvents.push(event)
+        },
+        oneose() {
+          // End of stored events - subscription is complete for initial fetch
+        }
+      })
+      
+      // Wait for events to be collected
+      await new Promise(resolve => setTimeout(resolve, 2000))
+      
+      // Close the subscription
+      subscription.close()
+      
+      // Deduplicate events by ID
+      const uniqueEvents = Array.from(
+        new Map(allEvents.map(event => [event.id, event])).values()
+      )
+
+      return uniqueEvents
+        .sort((a, b) => b.created_at - a.created_at)
+        .slice(0, limit)
+    } catch (error) {
+      console.error('Failed to fetch events:', error)
+      throw error
+    }
+  }
+
   /**
    * Fetch user profiles
    */