updated files for a prod env

.env.example

@@ -0,0 +1,24 @@
+# Copy to .env on each host and fill in real values — .env is gitignored,
+# never commit real secrets.
+#
+# Local dev machine: keep COMPOSE_FILE=docker-compose.dev.yaml (exposes
+# ports directly, hot-reloads source via bind mounts, includes adminer).
+#
+# Prod host: leave COMPOSE_FILE unset (docker-compose.yaml is Compose's
+# default filename) and set the rest to real values.
+
+# COMPOSE_FILE=docker-compose.dev.yaml
+
+# Domain Traefik routes to this app (bare domain — the compose file's
+# redirect middleware sends it to the www. subdomain).
+VIRTUAL_HOST=example.com
+
+# Postgres credentials — must be a real secret in prod (e.g. `openssl rand
+# -hex 32`), and must match the user/password embedded in DATABASE_URL below.
+POSTGRES_USER=postgres
+POSTGRES_PASSWORD=
+POSTGRES_DB=postgres
+DATABASE_URL=postgres://postgres:REPLACE_WITH_POSTGRES_PASSWORD@db:5432/postgres?sslmode=disable
+
+# Open Data Hub license key used by the Go importer.
+ODH_LICENCE_KEY=