Clean up the production compose file

Three leftovers: a named-volume block that nothing has used since the
move to bind mounts, the obsolete version key, and a comment claiming the
admin variables only apply to an empty database — they also decide whom
to promote when upgrading one that has users but no admin.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docker-compose.yml

@@ -1,19 +1,15 @@
-version: "3.8"
-
 # ─────────────────────────────────────────────
-# InkNote — Deploy on Docker VM
+# InkNote — deploy from the Gitea container registry
-# Pull images from Gitea container registry
 #
-# Usage:
+#   mkdir -p /srv/inknote/{db,uploads}
-#   mkdir -p /srv/inknote/db /srv/inknote/uploads
 #   chown -R 1000:1000 /srv/inknote
+#   cp .env.example .env && edit it        # secrets + first admin
 #   docker login gitea.honeyy.duckdns.org
-#   docker compose pull
+#   docker compose pull && docker compose up -d
-#   docker compose up -d
 #
-# Data lives under INKNOTE_DATA_DIR (default /srv/inknote) on the host.
+# Data lives under INKNOTE_DATA_DIR (default /srv/inknote) on the host, so
-# Back that path up together with the .env holding ENCRYPTION_KEY — the
+# whatever backs up the host also backs up InkNote. Back that path up together
-# database is encrypted and is unreadable without that key.
+# with the .env: the notes are encrypted and unreadable without ENCRYPTION_KEY.
 # ─────────────────────────────────────────────
 
 services:
@@ -25,7 +21,9 @@ services:
       - PORT=4000
       - JWT_SECRET=${JWT_SECRET}
       - ENCRYPTION_KEY=${ENCRYPTION_KEY}
-      # Only used when the database has no users at all: creates the first admin.
+      # Settles who the first administrator is — on an empty database by
+      # creating them, on an upgraded one by choosing whom to promote. Ignored
+      # entirely once an admin exists, so they can never reset anything.
       - INKNOTE_ADMIN_USER=${INKNOTE_ADMIN_USER:-}
       - INKNOTE_ADMIN_PASSWORD=${INKNOTE_ADMIN_PASSWORD:-}
       - NODE_ENV=production
@@ -51,7 +49,3 @@ services:
     depends_on:
       inknote-server:
         condition: service_healthy
-
-volumes:
-  inknote-data:
-  inknote-uploads: