calibre: replace with Calibre-Web-Automated on esh-docker-vm

Retire the linuxserver.io calibre + calibre-web pair. CWA
(crocodilestick/calibre-web-automated) is an all-in-one: combined web UI
with Calibre backend, auto-ingest via drop folder, scheduled metadata
maintenance — single container on :8083.

- Reuses the existing library at /mnt/books/calibre/calibre_library
  (NFS) and the existing calibre-web config at /opt/docker/conf/calibre-web,
  so user accounts and the book catalogue carry over.
- Requires NETWORK_SHARE_MODE=true (library is on NFS; SQLite WAL would
  corrupt otherwise).
- New drop-zone at /mnt/books/calibre/ingest; files placed there are
  ingested into the library and then removed.
- Loses the LSIO desktop Calibre GUI (ports 8082/8181/8281) — run
  Calibre locally if you need the desktop UI.

Old compose dirs (/opt/docker/compose/{calibre,calibre-web}) removed on
esh-docker-vm; old images can be pruned at leisure.

stacks/calibre-web-automated/.env.example

@@ -0,0 +1,40 @@
+# Calibre-Web-Automated tunables.
+#
+# Copy to .env on the host. The directory paths MUST exist and be
+# writable by PUID:PGID before the first container start.
+
+# Image pin
+CWA_VERSION=latest
+
+# Port on the host (and inside the container — CWA_PORT_OVERRIDE sets both).
+CWA_PORT=8083
+
+# UID/GID owning the mounted files. 2000:2000 matches what the old
+# calibre + calibre-web stacks used on esh-docker-vm.
+PUID=2000
+PGID=2000
+
+TZ=America/Los_Angeles
+
+# NETWORK_SHARE_MODE disables SQLite WAL. REQUIRED when /calibre-library
+# or /config is on NFS / SMB. Leave this on unless you move everything
+# to local disk.
+NETWORK_SHARE_MODE=true
+
+# Optional: enables the Hardcover metadata provider. Sign up at
+# hardcover.app and issue a token. Leave empty if unused.
+HARDCOVER_TOKEN=
+
+# Host directories — use the same library as the old stacks to keep the
+# book catalogue. Migrate the old calibre-web config in place.
+#
+# Example values for esh-docker-vm:
+#   CWA_CONFIG_DIR=/opt/docker/conf/calibre-web-automated
+#   CWA_INGEST_DIR=/mnt/books/calibre/ingest
+#   CWA_LIBRARY_DIR=/mnt/books/calibre/calibre_library
+#
+# ⚠  The ingest directory is a drop zone — files placed there are DELETED
+#    after CWA processes them into the library. Pick a dedicated folder.
+CWA_CONFIG_DIR=
+CWA_INGEST_DIR=
+CWA_LIBRARY_DIR=