feat: manual full-pass sync Langflow -> files -> DB+LFX with admin guide

README.md

@@ -122,9 +122,12 @@ Frontend (node lives in the `frontend` container):
 - `docker compose exec frontend npm run build` — typecheck + build.
 - Without a docker socket: VS Code "Attach to Running Container" → frontend.
 
-Flow workflow: design in Langflow → export into `backend/flows/<name>.json`
-(`--pull`, or UI download) → commit → the watcher deploys it automatically.
-Deleting a file removes the flow including its runs (git keeps the JSON).
+Flow workflow: design in Langflow → press "Aus Langflow synchronisieren"
+in Verwaltung (manual full pass: Langflow → `backend/flows/<name>.json` →
+DB + LFX deploy) → commit. File-only alternatives: `scripts/sync_flows.py
+--pull --sync`, UI download, or the single-flow import by Langflow ID. The
+watcher deploys file edits automatically. Deleting a file removes the flow
+including its runs (git keeps the JSON).
 
 ## Production (self-hosted — TLS/reverse proxy required, not included)