fix: resolve linter errors

- Add missing useMemo import to Bookmarks component
- Remove unused NostrEvent import from contactService
- All ESLint checks passing
- All TypeScript type checks passing

src/components/Bookmarks.tsx

@@ -1,4 +1,4 @@
-import React, { useState, useEffect } from 'react'
+import React, { useState, useEffect, useMemo } from 'react'
 import { useParams } from 'react-router-dom'
 import { Hooks } from 'applesauce-react'
 import { useEventStore } from 'applesauce-react/hooks'

src/services/contactService.ts

@@ -1,6 +1,5 @@
 import { RelayPool, completeOnEose } from 'applesauce-relay'
 import { lastValueFrom, takeUntil, timer, toArray } from 'rxjs'
-import { NostrEvent } from 'nostr-tools'
 
 /**
  * Fetches the contact list (follows) for a specific user