fix: use felhom-data/appdata/ path for HDD volume mounts

Compose templates were mounting app data at ${HDD_PATH}/appdata/ instead
of ${HDD_PATH}/felhom-data/appdata/ as designed in the v0.26.0+ path
structure. Affects: nextcloud, immich, paperless-ngx, romm.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

templates/immich/docker-compose.yml

@@ -9,7 +9,7 @@
 #   DB_PASSWORD     - PostgreSQL password (auto-generated)
 #
 # Storage layout:
-#   User photos/videos → ${HDD_PATH}/appdata/immich  (HDD, host path)
+#   User photos/videos → ${HDD_PATH}/felhom-data/appdata/immich  (HDD, host path)
 #   PostgreSQL data    → immich_postgres_data          (named volume, NVMe)
 #   ML model cache     → immich_ml_cache               (named volume, NVMe)
 #   Redis data         → immich_redis_data             (named volume, NVMe)
@@ -36,7 +36,7 @@ services:
       - IMMICH_MACHINE_LEARNING_URL=http://immich-machine-learning:3003
       - TZ=Europe/Budapest
     volumes:
-      - ${HDD_PATH}/appdata/immich:/usr/src/app/upload
+      - ${HDD_PATH}/felhom-data/appdata/immich:/usr/src/app/upload
     networks:
       - traefik-public
       - immich-internal