chore(07-02): update entrypoint.sh to document YAML config

- Add comments about D-06 load order and YAML config path
- Add warning if backend.yaml is missing
- Remove any implied inventory.env dependencies

backend/entrypoint.sh

@@ -19,6 +19,13 @@ echo "🐳 [Docker] LOGS_DIR=${LOGS_DIR:-/app/logs}"
 export DATA_DIR="${DATA_DIR:-/app/data}"
 export LOGS_DIR="${LOGS_DIR:-/app/logs}"
 
+# [D-06] Configuration - Config is loaded from /app/config/ (YAML format)
+# System environment variables override YAML config (D-06 load order).
+# No inventory.env fallback is used by the backend application.
+if [ ! -f "/app/config/backend.yaml" ]; then
+    echo "⚠️  [Docker] WARNING: /app/config/backend.yaml not found! Using defaults."
+fi
+
 # Run shared first-run initialization
 echo "🐳 [Docker] Running data initialization..."
 bash /app/scripts/init_data.sh