fix: remove unused imports and dead code to clear ESLint errors

packages/admin/src/routes/_authenticated/lessons/sessions/$sessionId.tsx

@@ -67,7 +67,7 @@ function SessionDetailPage() {
     enabled: !!session?.enrollmentId,
   })
 
-  const { data: instructorData } = useQuery({
+  useQuery({
     ...instructorDetailOptions(session?.substituteInstructorId ?? enrollment?.instructorId ?? ''),
     enabled: !!(session?.substituteInstructorId ?? enrollment?.instructorId),
   })

packages/admin/src/routes/_authenticated/lessons/sessions/index.tsx

@@ -11,7 +11,6 @@ import { Badge } from '@/components/ui/badge'
 import { Input } from '@/components/ui/input'
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
 import { Search, LayoutList, CalendarDays, ChevronLeft, ChevronRight } from 'lucide-react'
-import { useAuthStore } from '@/stores/auth.store'
 import type { LessonSession } from '@/types/lesson'
 
 export const Route = createFileRoute('/_authenticated/lessons/sessions/')({