FTS via dedicated read-only connection (match_bm25 breaks across ATTACH catalogs)

app.py

@@ -152,15 +152,19 @@ async def lifespan(app: FastAPI):
         has_param = False
     load_table(DATASET_CFG, "dataset_cards", has_param=False)
     load_table(MODEL_CFG, "model_cards", has_param=has_param)
-    # Optional: attach the prebuilt card-text FTS db (read-only, disk-backed).
-    # Any failure degrades hybrid search to vector-only rather than blocking boot.
+    # Optional: open the prebuilt card-text FTS db on its OWN connection.
+    # (Not ATTACHed: the fts match_bm25 macro references its internal schema
+    # unqualified, which breaks across catalog boundaries.) Any failure
+    # degrades hybrid search to vector-only rather than blocking boot.
+    global fts_con
     try:
         fts_path = hf_hub_download(EMBEDDINGS_REPO, FTS_FILE, repo_type="dataset")
-        con.execute("INSTALL fts; LOAD fts;")
-        con.execute(f"ATTACH '{fts_path}' AS cardtext (READ_ONLY)")
-        STATE["fts_cards"] = con.execute("SELECT count(*) FROM cardtext.cards").fetchone()[0]
+        fts_con = duckdb.connect(fts_path, read_only=True)
+        fts_con.execute("INSTALL fts; LOAD fts;")
+        STATE["fts_cards"] = fts_con.execute("SELECT count(*) FROM cards").fetchone()[0]
         logger.info(f"card-text FTS attached: {STATE['fts_cards']:,} cards")
     except Exception as e:
+        fts_con = None
         STATE["fts_cards"] = None
         logger.warning(f"card-text FTS unavailable ({e}); hybrid=vector-only")
     try:
@@ -298,14 +302,17 @@ def _emb_of(table, repo_id):
     return row[0] if row else None
 
 
+fts_con = None
+
+
 def _bm25_ids(kind: str, text: str, n: int) -> list:
     """Top-n repo ids by BM25 over full card text (empty if FTS unavailable)."""
-    if not STATE.get("fts_cards"):
+    if fts_con is None:
         return []
-    rows = con.execute(
+    rows = fts_con.execute(
         """SELECT id FROM (
-               SELECT id, cardtext.fts_main_cards.match_bm25(doc_id, ?) AS s
-               FROM cardtext.cards WHERE repo_type = ?
+               SELECT id, fts_main_cards.match_bm25(doc_id, ?) AS s
+               FROM cards WHERE repo_type = ?
            ) WHERE s IS NOT NULL ORDER BY s DESC LIMIT ?""",
         [text, kind, int(n)],
     ).fetchall()