fix(import): decrypt owner-encrypted PDFs with pdfcpu; add imports bucket to minio-init

- parsePDF now attempts to strip encryption via pdfcpu (empty user password)
  before handing bytes to dslipak/pdf — fixes '256-bit encryption key' error
  on publisher PDFs that use owner-only encryption (copy/print restrictions)
- Add pdfcpu v0.11.1 as direct dependency (was already indirect)
- docker-compose.yml minio-init: add 'imports' and 'translations' buckets
  so a fresh deploy creates all required buckets

docker-compose.yml

@@ -58,6 +58,8 @@ services:
         mc mb --ignore-existing local/audio;
         mc mb --ignore-existing local/avatars;
         mc mb --ignore-existing local/catalogue;
+        mc mb --ignore-existing local/translations;
+        mc mb --ignore-existing local/imports;
         echo 'buckets ready';
       "
     environment: