Fix calibre: switch to NFS systemd automount bind mounts

CIFS uid/gid mismatch caused Permission denied on files created via NFS
(cert.key, .gnupg, etc. owned by uid=99 with mode 600/700; SMB user
can't access them server-side). NFS maps uid/gid directly, avoiding the
issue. Use hard mount so spin-up blocks briefly instead of returning EIO.

calibre/docker-compose.yaml

@@ -1,6 +1,7 @@
 # https://thebloody.cloud/posts/Installing-Web-Calibre-in-Docker/
-# NFS volumes replaced with systemd automount bind mounts (/mnt/media)
-# to avoid SQLite SQLITE_IOERR on soft NFS when unRAID drives spin down.
+# Uses NFS via systemd automount (/mnt/nas_books) + bind mounts.
+# Docker NFS named volumes caused SQLITE_IOERR on soft timeouts; systemd
+# automount with hard NFS blocks briefly on spin-up instead of returning EIO.
 
 networks:
   default:
@@ -21,8 +22,8 @@ services:
       - VIRTUAL_PORT=8080
       - LETSENCRYPT_HOST=calibre.kolpacksoftware.com
     volumes:
-      - /mnt/media/books/calibre:/config
-      - /mnt/media/books/calibre-import:/calibre-import
+      - /mnt/nas_books/calibre:/config
+      - /mnt/nas_books/calibre-import:/calibre-import
     ports:
       - 8090:8080
       - 8091:8081