Revert "Add missing admin action files and navigation links"

This reverts commit 41be6835bf.

src/app/admin/import/effects/page.tsx

@@ -1,12 +0,0 @@
-// src/app/[locale]/admin/import/effects/page.tsx
-import { redirect } from 'next/navigation'
-import { canAccess, getAdminContext, PERMS } from '@/lib/permissions'
-import { ImportEffectsClient } from './import-effects-client'
-
-export default async function ImportEffectsPage(_props: { params: Promise<{ locale: string }> }) {
-  const { session, permissions } = await getAdminContext()
-  if (!canAccess(permissions, PERMS.ASSETS_IMPORT, session.user.rank)) {
-    redirect('/admin')
-  }
-  return <ImportEffectsClient />
-}