fix(BUG-C3,C-03,M-13): wrap synchronous Neo4j session in run_in_executor inside async WebSocket; fix feed change-detection to compare full ID set not just first scraped_at

api/main.py

@@ -169,34 +169,49 @@ async def websocket_feed(websocket: WebSocket):
             payload = {"type": "feed", "at": datetime.now().isoformat()}
             if driver:
                 try:
-                    with driver.session() as s:
-                        feed_rows = s.run(
-                            "MATCH (n) WHERE labels(n)[0] IN $labels "
-                            "AND n.scraped_at IS NOT NULL "
-                            "RETURN labels(n)[0] AS label, "
-                            "coalesce(n.name, n.title, n.company_name, n.id) AS name, "
-                            "n.scraped_at AS scraped_at, n.id AS id, n.source AS source "
-                            "ORDER BY n.scraped_at DESC LIMIT 8",
-                            labels=_FEED_LABELS
-                        ).data()
-                        current_at = feed_rows[0].get("scraped_at") if feed_rows else None
-                        # LOGIC FIX: skip push if data has not changed since last send
-                        if current_at and current_at == last_scraped_at and feed_rows:
-                            await asyncio.sleep(15)
-                            continue
-                        last_scraped_at = current_at
-                        if feed_rows:
-                            payload["items"]   = feed_rows
-                            payload["message"] = (
-                                feed_rows[0].get("label", "Entity") + ": " +
-                                feed_rows[0].get("name", "-")
-                            )
-                        else:
+                    loop = asyncio.get_event_loop()
+
+                    def _query_feed():
+                        # C-03 / BUG-C3 FIX: synchronous Neo4j driver MUST run
+                        # in a thread pool -- calling driver.session() directly
+                        # inside async def blocks the entire uvicorn event loop
+                        # while waiting for network I/O to Neo4j AuraDB.
+                        with driver.session() as s:
                             rows = s.run(
-                                "MATCH (n) RETURN labels(n)[0] AS t, count(n) AS c"
+                                "MATCH (n) WHERE labels(n)[0] IN $labels "
+                                "AND n.scraped_at IS NOT NULL "
+                                "RETURN labels(n)[0] AS label, "
+                                "coalesce(n.name, n.title, n.company_name, n.id) AS name, "
+                                "n.scraped_at AS scraped_at, n.id AS id, n.source AS source "
+                                "ORDER BY n.scraped_at DESC LIMIT 8",
+                                labels=_FEED_LABELS
                             ).data()
-                            payload["stats"]   = {r["t"]: r["c"] for r in rows if r["t"]}
-                            payload["message"] = "Feed active -- run /admin/pipeline to ingest data"
+                            if not rows:
+                                stats = s.run(
+                                    "MATCH (n) RETURN labels(n)[0] AS t, count(n) AS c"
+                                ).data()
+                                return {"rows": [], "stats": {r["t"]: r["c"] for r in stats if r["t"]}}
+                            return {"rows": rows, "stats": {}}
+
+                    feed_result = await loop.run_in_executor(None, _query_feed)
+                    feed_rows   = feed_result["rows"]
+
+                    # M-13 FIX: compare full set of IDs, not just first scraped_at
+                    current_ids = frozenset(r.get("id","") for r in feed_rows)
+                    if current_ids and current_ids == last_scraped_at:
+                        await asyncio.sleep(15)
+                        continue
+                    last_scraped_at = current_ids
+
+                    if feed_rows:
+                        payload["items"]   = feed_rows
+                        payload["message"] = (
+                            feed_rows[0].get("label", "Entity") + ": " +
+                            feed_rows[0].get("name", "-")
+                        )
+                    else:
+                        payload["stats"]   = feed_result["stats"]
+                        payload["message"] = "Feed active -- run /admin/pipeline to ingest data"
                 except Exception as db_err:
                     logger.debug(f"[WS] DB query error: {db_err}")
                     payload["message"] = "Feed active -- database query pending"