Fix: backend waits for Neo4j bolt before starting uvicorn

docker/supervisord.conf

@@ -40,7 +40,7 @@ priority=99
 
 # ── FastAPI backend ────────────────────────────────────────────────────────────
 [program:backend]
-command=python3 -m uvicorn main:app --host 127.0.0.1 --port 8000 --workers 2
+command=bash -c "until (echo > /dev/tcp/127.0.0.1/7687) 2>/dev/null; do echo '[backend-wait] Neo4j not ready, retrying...'; sleep 5; done && echo '[backend-wait] Neo4j bolt ready — starting uvicorn' && python3 -m uvicorn main:app --host 127.0.0.1 --port 8000 --workers 2"
 directory=/app/backend
 environment=
     NEO4J_URI="bolt://127.0.0.1:7687",