- Added `constants.mjs` defining `STORAGE_DIR` and `GRAPH_FILE`.
- Replaced hard‑coded path strings in `agent.mjs`, `build_graph.mjs`, and `ingest.mjs` with imports from the new constants module.
- Updated console log in `ingest.mjs` to reference `STORAGE_DIR`.
- Adjusted `GRAPH_FILE` path to `./graphology/graph.json` via the constant.