userdata layout: repoint customer-content mounts to ${USERDATA_PATH}

Move every shared-media + ingest mount off ${HDD_PATH}/media onto the new
${USERDATA_PATH}/... convention (controller injects USERDATA_PATH = <namespace>/userdata):
- jellyfin/emby/plex: media:/media:ro ; navidrome: media/music:ro
- audiobookshelf (user 1000:1000): media/{audiobooks,podcasts}
- komga (user 1000:1000): media/comics
- calibre-web (UMASK=002): library->media/books, ingest->import/calibre
- radarr/sonarr (UMASK=002): media/{movies,tv} + downloads (sibling, same FS)
- romm: ROM library -> userdata/roms (browsable); resources stay in appdata
- immich: + external library media/photos:/external/photos:ro (registration is a
  post-deploy admin step — flagged in compose + .felhom.yml)
- paperless: consume -> import/paperless (USERMAP 1000)
- nextcloud: unchanged (fully app-managed)
.felhom.yml first_steps updated for the new browsable drop-zones.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

templates/calibre-web/docker-compose.yml

@@ -5,12 +5,13 @@
 #
 # Environment variables:
 #   DOMAIN          - Your domain (e.g., demo-felhom.eu)
-#   HDD_PATH        - E-könyvtár útvonal
+#   USERDATA_PATH   - Ügyfél-tartalom gyökér (<namespace>/userdata)
 #
-# Storage layout:
-#   App config/DB    → calibre_web_config       (named volume, NVMe)
-#   Book ingest      → ${HDD_PATH}/media/books/ingest   (HDD, drop files here — processed and removed)
-#   Calibre library  → ${HDD_PATH}/media/books/library  (HDD, Calibre library storage)
+# Storage layout (felhom userdata convention):
+#   App config/DB    → calibre_web_config              (named volume, NVMe)
+#   Calibre library  → ${USERDATA_PATH}/media/books     (browsable, írható)
+#   Book ingest      → ${USERDATA_PATH}/import/calibre  (drop-zone — processed and removed)
+# Run-identity: PUID/PGID 1000 (shared content group); UMASK=002 so output is group-writable.
 #
 # First-time setup:
 #   Default login: admin / admin123 — change immediately!
@@ -24,10 +25,11 @@ services:
       - TZ=Europe/Budapest
       - PUID=1000
       - PGID=1000
+      - UMASK=002
     volumes:
       - calibre_web_config:/config
-      - ${HDD_PATH}/media/books/ingest:/cwa-book-ingest
-      - ${HDD_PATH}/media/books/library:/calibre-library
+      - ${USERDATA_PATH}/import/calibre:/cwa-book-ingest
+      - ${USERDATA_PATH}/media/books:/calibre-library
     networks:
       - traefik-public
     deploy: